Term
|
Definition
| Pituitary, thyroid, adrenal, parathyroid, pancreatic islets |
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Term
| Example of autocrine action |
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Definition
| Local, binding receptor on surface of same cell; used by prostaglandins (eicosanoids) in uterine smooth muscle contraction and pregnancy |
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Term
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Definition
| Regulates tone of smooth muscle cells and many other jobs (different flash card) |
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Term
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Definition
| Non-polar, uncharged; carrier proteins in plasma; secreted immediately (usually) |
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Term
|
Definition
| Dissolve well in water; polar, charged; stored in secretory vesicles |
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Term
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Definition
| Derived from tyrosine- catecholamines, thyroid hormones, dopamine, norepinephrine, epinephrine |
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Term
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Definition
| Produced by pituitary gland as RF, act on peripheral endocrine glands; also insulin made by endocrine pancreas |
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Term
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Definition
| Induces conformation for cross-binding of pro-insulin, cleaved in Golgi, packaged in secretory vesicle with insulin - best measurement of endogenous insulin production |
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Term
| Hydrophilic hormone signaling |
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Definition
| Receptors on cell surface, signal through 2nd messengers (GPCR or TRK receptor) |
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Term
| Hydrophobic hormone precursors |
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Definition
Cholesterol --> steroids
Tyrosine --> thyroid hormones
Arachadonic aicd --> eicosanoids |
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Term
| Hydrophobic hormones with Type I Receptors and action |
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Definition
| Steroid hormones; hormone-receptor complex enter nucleus, bind HRE, promote gene expression |
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Term
| Hydrophobic hormones with Type II Receptors and action |
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Definition
| Vitamin A, Vitamin D, retinoids, thyroid hormones; receptors already bound to DNA, receptors repress gene expression when inactive |
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Term
| Releasing hydrophilic hormones |
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Definition
| Accumulate when secretion not required; PLC makes IP3, Ca released in cytosol, facilitate fusion of vesicles with hormones to plasma membrane; cAMP and cGMP modulate process of secretion too |
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Term
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Definition
| Time for 1/2 to disappear from plasma, depends on % bound to carrier protein at any given time |
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Term
|
Definition
| mg/min removed / [mg/ml] in plasma = ml plasma/min |
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Term
| Methods of hormone removal |
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Definition
| Uptake and degradation by target cell, metabolic degradation in the liver, urinary or biliary excretion |
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Term
|
Definition
| mAb bind radioactive hormone; higher concentration of hormone leads to less radioactive antibody complex |
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Term
|
Definition
| Ab bound to substrate, catalyze reaction to make fluorescent product - intensity related to hormone concentration |
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Term
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Definition
| Compensate for increased hormone plasma levels, leads to reduced affinity of hormone for receptor even if normal hormone levels return |
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Term
| Reduced responsiveness of hormone receptor |
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Definition
| Increased hormone concentration doesn't produce relevant increase in biological response |
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Term
| Reduced sensitivity of hormone receptor |
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Definition
| Shift to right in dose-response curve - need high concentration of hormone to induce 50% maximal response |
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Term
| Hypophysiotropic hormones |
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Definition
| Releasing hormones - released from 1st capillary bed in hypothalamus and go to 2nd capillary bed in AHP, where released to trophic cells |
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Term
|
Definition
| Present in supraoptic and paraventricular nuclei of hypothalamus; project into posterior pituitary, release ADH and oxytocin |
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Term
| Cells releasing oxytocin and vasopressin |
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Definition
| Magnocellular neurons of supraoptic and paraventricular nuclei in the median eminence of hypothalamus |
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Term
|
Definition
Secreted by paraventricular nuclei of hypothalamus
41 amino acids
Stimulates POMC gene expression and ACTH secretion by corticotrophs |
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Term
|
Definition
39 amino acids
Secreted by corticotrophs, go to adrenal cortex to stimulate glucocorticoid and weak androgen production
Tropic and trophic |
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Term
|
Definition
3 amino acid peptide
Stimulates XP of alpha and beta subunits of TSH and TSH secretion of TSH by thyrotrophs
Stimulates PRL synthesis by lactotrophs |
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Term
|
Definition
Glycoprotein secreted by thyrotrophs
Stimulates T4, T3 production by follicular cells in thyroid
Tropic and trophic effect on thyroid |
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Term
|
Definition
40/44 amino acids
Produced in arcuate and ventromedial nuclei of hypothalamus
Stimulates GH gene expression and secretion by somatotrophs |
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Term
|
Definition
191 aa chain secreted by somatotrophs
Promotes body growth, TAG lipolysis, counterregulatory
Inhibits insulin action, IFG-1 must be involved also |
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Term
|
Definition
| 10 aa chain stimulating FSH and LH secretion by gonadotrophs |
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Term
|
Definition
| Glycoprotein promoting development of ovarian follicles and regulation of spermatogenesis |
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Term
|
Definition
Glycoprotein promoting ovulation, formation of corpus luteum
Stimulates estrogen and progesterone formation
Testosterone production by testes |
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Term
|
Definition
14 amino acid chain, aka somatostatin
Released by anterior periventricular region of hypothalamus
Inhibit GH secretion (somatotroph), TSH secretion (thyrotroph) |
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Term
|
Definition
| Catecholamine, inhibits PRL synthesis and secretion by lactotrophs |
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Term
|
Definition
| 199 amino acid chain, essential for milk production by lactating mammary gland (not tropic or trophic) |
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Term
|
Definition
| Endocrine cell hormones give negative feedback to both hypothalamus and anterior pituitary; sometimes positive feedback to somatostatin; TH and EH seen in blood, too little RH |
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Term
| Tropic vs. trophic effect |
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Definition
Tropic - exert action on other endocrine gland
Trophic - promote healthy state of target cells affection - growth |
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Term
| Glands modulated by H-P axis |
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Definition
| Adrenal gland, thyroid gland, testes, ovaries |
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Term
|
Definition
| Glucocorticoids inhibit ACTH and CRH release; expect low ACTH when high glucocorticoids; stress increases ACTH to make more glucocorticoids |
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Term
| CRH action in pituitary cell |
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Definition
| Receptor, Gs, adenylyl cyclase, cAMP, PKA, phoshporylation, increase POMC mRNA, POMC --> ACTH and beta-LPH |
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Term
|
Definition
| Pulsatile, circadian rhythm, highest in morning, lowest while asleep |
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Term
|
Definition
| Tonic pattern of secretion, constant levels reach pituitary |
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Term
|
Definition
| Gq, PLC, PIP2, DAG and IP3, PKC and Ca, increase transcription of 2 TSH subunits, promote secretion |
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Term
|
Definition
| T3 and T4 decrease TRH, TSH, positive feedback on somatostatin; highest in early morning |
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Term
| Counterregulatory hormones |
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Definition
| Glucagon, epinephrine, cortisol, growth hormone |
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Term
|
Definition
| Neonatal growth, metabolism of carbs, lipids and proteins; counteract insulin, increase plasma glucose |
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Term
|
Definition
| GH and IGF-I have negative feedback on GHRH (and GH) and positive feedback on somatostatin |
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Term
| GH action on somatotrophs |
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Definition
| increase cAMP, PKA while SRIF reduces these pathways, lead to GH release |
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Term
|
Definition
| Stimulate lipolysis in adipose by stimulating HSL to increase adipocyte responsiveness to lipolytic stimuli; stimulate AA transport in muscle |
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Term
|
Definition
| Synthesize trophic hormone IGF-I |
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Term
|
Definition
70 amino acid peptide hormone, made in liver, mitogenic and trophic effect on many tissues
Autocrine signal to promote chondrocyte proliferation to enlarge metaphysis and end up with osteoblasts making bone matrix |
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Term
|
Definition
| GH bind receptor on prechondrocyte to differentiate into chondrocyte and secrete IGF-I, which signals to promote chondrocyte proliferation and enlarge metaphysis and end up with osteoblasts producing bone matrix |
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Term
|
Definition
| Pulsatile, highest values around midnight in stage 3-4 slow wave sleep; higher at all times of day in adolescents than adults; increased with exercise or emotional/physical stress |
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Term
|
Definition
| TKR, act by JAK/STAT pathway, then phoshporylation |
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Term
|
Definition
| traditional TKR, using protein phosphorylation |
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Term
|
Definition
| Make muscles and adipocytes resistant to insulin activity leading to hyperglycemia resembling DM Type II |
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|
Term
| Prolactin roles and stimulation |
|
Definition
| Stimulate milk production in mammary gland and breast growth (usually inhibited by PIF), suckling of baby blocks dopamine; inhibits LH and FSH production; positive feedback |
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Term
|
Definition
| Prolactin, estrogens and oxytocin |
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Term
|
Definition
| Affects entire pituitary gland (trauma or vascular injury) |
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|
Term
| Partial damage to pituitary |
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Definition
| Often affects single cell type, single hormone |
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Term
|
Definition
| Affect 1 type of secreting cell, 1 hormone; can lead to bitemporal hemianopsia |
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Term
|
Definition
| Altered eyesight due to pituitary adenoma if growth leaves sella turcica and pinches of optic pile |
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Term
|
Definition
| Excess GH in adulthood; thicker bones, indicative facial features |
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Term
|
Definition
| Excess GH in childhood before epiphyseal fusion - taller |
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Term
|
Definition
| Childhood GH deficiency - short with proportional limbs and torso |
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Term
|
Definition
AVP, vasopressin - made by supraoptic + paraventricular nuclei
Respond to increased plasma osmolarity or hypovolemia
Act on V2 and V1 receptors |
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Term
|
Definition
| AVP - Gs, cAMP, increase AQP2 in nephron collecting duct, increase water permeability, leading to concentrated urine and more water retention |
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Term
|
Definition
| AVP - PLC, IP3, Ca, contract smooth muscle and arterioles, increase peripheral resistance, vasoconstriction, increase BP |
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Term
|
Definition
Excessive diuresis due to lack of AVP
Polyuria, polydipsia, no hyperglycemia, no hyperglycosuria |
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|
Term
| Oxytocin stimulation and role |
|
Definition
Stimulation: sight/sound/smell of infant, dilation of cervix in labor and orgasm, neural input during childbirth
Role: induce contraction of myoepithelial cells in lactation and uterus during labor |
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Term
|
Definition
Expressed by adipose tissue, plasma levels rise with more fat deposit, exogenous ineffective at reducing appetite
Leptin receptors in hypothalamus, affecting TSH and GH |
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|
Term
| How does thyroid hormone make changes? |
|
Definition
| Activity is exerted at the gene expression level - though technically not necessary for life |
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Term
|
Definition
| Synthesized and stored in follicles, colloid in follicle lumen is 10-25% thyroglobulin which has T3, T4 stored on it; unusual for hydrophobic hormones - EXCEPTION |
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|
Term
| Effectiveness of replacement therapy |
|
Definition
| Works for thyroid hormone because tonic secretion at all times, not as good for adrenal hormones which act at certain times |
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Term
|
Definition
| 150 µg/day RDA - deficiency can lead to hypothyroidism |
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|
Term
| Sodium/Iodine Symporter (NIS) |
|
Definition
| Uptake from blood using Na gradient set up by Na/K ATPase, low blood iodine stimulates NIS activity |
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|
Term
|
Definition
| Oxidizes iodide to iodine, oxidizes attaches I to make MIT and DIT, couples precursors to make T3 and T4 |
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Term
|
Definition
| Channel by which Iodine enters lumen, insensitive to tSH, only based on iodide concentration |
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Term
|
Definition
| T4 secreted 5x more than T3; linked to Thyroglobulin until TSh hormone stimulation |
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|
Term
|
Definition
| Inhibits thyroid peroxidase (TPO), treatment for hyperthyroidism |
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|
Term
|
Definition
| Present on pseudopodia upon TSH stimulation, leading to uptake of colloid into follicular cells in endosomes |
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|
Term
| TSH stimulation action on thyroid cells |
|
Definition
| Follicular cells extend pseudopodia with Megalin receptor, re-uptake colloid in endosomes, fuses with lysosomes to hydrolyze thyroglobulin, release T3 and T4 into capillaries and recycle everything else; TSH stimulates Megalin expresion, NIS synthesis, TPO activation |
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|
Term
| Thyroxin-binding globulin |
|
Definition
Glycoprotein secreted by liver, binds 70% T4, 80% T3
Increased in pregnancy |
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Term
| T3 and T4 binding and free in blood |
|
Definition
| Most to TBG, some to transthyretin and albumin, <1% free, leading to long half-life (1 day T3, 7 days T4) |
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Term
|
Definition
| T3 --> Type II THR --> complex with Retnoid X Receptor, bind TRE on DNA --> several hours for effect due to changes needed in gene expression on respiration, morphology, ion homeostasis |
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Term
|
Definition
| T4 --> T3 peripherally in liver, kidneys, thyroid; contains selenocysteine |
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Term
|
Definition
| T4 --> T3 in cytosol of skeletal muscle, CNS, pituitary, placenta; contains selenocysteine |
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|
Term
|
Definition
| Liver, kidneys, deactivate T3 and T4 by iodine removal; Reverse T3 - 40% T4 deiodination product, mostly inactive on THR; contains selenocysteine; inactivation occurs by inner ring deiodination |
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Term
|
Definition
| Less active in fetus, fasting, trauma, illness |
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|
Term
| T4 production in fasting and illness |
|
Definition
| Not increased, Deiodinase 2 in CNS and pituitary make enough T3 |
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Term
|
Definition
| Result of increased trophic effect of TSH for long time leading to enlarged thyroid gland |
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|
Term
| T3 impact on mitochondria |
|
Definition
| May regulate its use of O2, increased ml/min O2 in hyperactive gland |
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|
Term
| Major effects of thyroid hormones |
|
Definition
| Brain maturation in fetus, regulating GH release, regulating BMR, thermogenesis |
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|
Term
|
Definition
| Impaired TRH or TSH production by hypothalamic or pituitary failure |
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|
Term
|
Definition
| Autoimmune Ab directed against TPO enzyme or TSH receptor leading to destruction of gland - type of primary hypothyroidism; tissue atrophy/destruction of thyroid |
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|
Term
|
Definition
Most common hypothyroidism with insufficient iodide in diet
Weight gain, reduced BMR, fatigue, cold sensitive, peripheral edema, goiter; osmotic water retention leads to swollen skin in face, hand or feet in severe case |
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|
Term
|
Definition
| Irreversible mental retardation if untreated - macroglossia, less active, constipation, small with poor feeding |
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Term
|
Definition
Primary hyperthyroidism with autoAb to TSH receptor, overstimulation of thyroid gland
Weight loss, fatigue, increased BMR, muscle wasting, enlarged gland due to DIFFUSE TOXIC GOITER - can see protruding eye bulb - diagnose with uptake of radioactive iodine - more in women |
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|
Term
| Living without adrenal function |
|
Definition
| Cannot survive without continuous intake of water, salt, energy metabolites - no easy replacement therapy |
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|
Term
| Primary hormone products of adrenal cortex regions |
|
Definition
Zona glomerulosa - mineralicorticoids - aldosterone
Zona fasciculata and reticularis - glucocorticoids and weak androgens - cortisol, corticosterone, DHEA, androstenedione |
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Term
|
Definition
| Not very specific, glucocorticoids can act on it a bit - 11beta-dehydrogenase can inactivate cortisol to cortisone to allow only aldosterone to act on receptor in peripheral tissue |
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Term
|
Definition
| Converts active cortisol to inactive cortisone in peripheral tissues to allow mineralocorticoid receptors to only be activated by aldosterone |
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|
Term
| Role of androgenic steroids |
|
Definition
| Main androgenic hormones in blood of female; most androgens made by testes in male - support prepubescent development (mostly masculinizing hormone) |
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|
Term
| Storage of adrenal cortex hormones |
|
Definition
| Produced on demand, NOT stored |
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|
Term
| Cholesterol side-chain cleavage enzyme |
|
Definition
| Converts cholesterol to pregnenolone in mitochondria, first step in synthesis of all adrenal cortex hormones |
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Term
|
Definition
| Cholesterol to pregnenolone by cholesterol side-chain cleavage enzyme; convert to 11-deoxycorticosterone by 21-hydroxylase; convert to corticosterone by 3beta-hydroxysteroid dehydrogenase; convert to aldosterone by aldosterone synthase (only in zona glomerulosa) |
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Term
|
Definition
| Cholesterol to pregnenolone by cholsterol side-chain cleavage enzyme; convert to 17OH pregnenolone by 17a-hydrolyase; 3beta-hydroxysteroid dehydrogenase and 21-hydroxylase to deoxycortisol; 11beta-hydrolyase to cortisol |
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Term
|
Definition
| Cholesterol to pregnenolone by cholesterol side-chain cleavage enzyme; conert to 17aOH pregnenolone by 17a-hydroxylase; lyase activity of 17a-hydroxylase forms DHEA - can form androstenedione from here |
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|
Term
|
Definition
| Necessary for production of cortisol, DHEA, androstenedione - only present in zona fasciculata and zona reticularis |
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|
Term
| Location of adrenal cortex hormone synthesis |
|
Definition
| Pregnenolone formed in mitochondria, rest of formation occurs in SER |
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Term
|
Definition
| Beginning of 17aOH-pregnenolone lyase activity, starting around age 7-8 before puberty, leading to dvelopment of pubic and axillary hair |
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|
Term
| DHEA and androstenedione conversion |
|
Definition
| Can be converted to testosterone or more potent DHT or estradiol in peripheral tissues; most synthesis in adrenal cortex, especially in females |
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|
Term
| 21-hydroxylase deficiency |
|
Definition
| Reduced mineralicorticoids and glucocorticoids with increased precursors - virilization and hirsutism in females; salt wasting, hypovolemia, hypotension in severe cases |
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|
Term
| ACTH effect on adrenal cortex hormones |
|
Definition
| ACTH regulates glucocorticoids and androgens, minimally affect aldosterone; acts through melanocortin-2 receptor and stimulation of cholesteryl ester hydrolase for cholesterol to enter mitochondria; long-term regulation at gene expression level |
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|
Term
|
Definition
| Converts corticosterone to cortisol to make it more active peripherally |
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|
Term
| ACTH, cortisol secretion timing |
|
Definition
| Pulsatile, 10 bursts/day, mostly diurnal, highest right before waking; abolished by coma/blindness/constant light and dark |
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Term
|
Definition
| Stress, pain, trauma, infection, exercise - can lead to adrenal hypertrophy in chronic stress; macrophages release ILs in trauma and infection; beta-endorphin analgesic when pain |
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|
Term
| Adrenal steroid binding in blood |
|
Definition
| 90% bound to CBG (liver glycoprotein); 6-7% bound to albumin, 3-4% free, long half-life |
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|
Term
|
Definition
| Cortisol and androgens bound to glucuronic acid and sulfuric acid respectively to increase water solubility for disposal in urine - can be measured to assess adrenal activity |
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|
Term
| Adrenal steroid receptor type |
|
Definition
| Type I receptor; glucocorticoid binds GRE, promote gene expression, synthesis - takes hours for effects |
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|
Term
| Glucocorticoids in prolonged fast |
|
Definition
| Lead to protein breakdwon in skeletal muscle to make more glucose; increase enzymes in gluconeogenesis, mobilize use of stored fat by activating HSL |
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|
Term
| Glucocorticoid as anti-inflammatory |
|
Definition
| Reduce NO, decrease capillary permeability; synthesize lipocortin to reduce prostaglandins and leukotrienes; decrease # of T-cells, B-cells and mast cells (therapy to reduce immune response) |
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|
Term
| Additional roles of glucocorticoids |
|
Definition
| Bone growth regulation, excrete excess H2O (inhibit ADH), regulate thyroid hormones, regulate progesterone/estrogen activity |
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|
Term
|
Definition
| Regulate by Angiotensin II in renin-angiotensin system and by K levels (increase), child in extracellular fluid volume |
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|
Term
| Aldosterone effect on kidney |
|
Definition
| Na retention, K excretion, H2O retention, increase BP - act at distal tubule and collecting duct, increase Na channels; increase Na/K ATPase on basolateral side of cells |
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|
Term
| ACTH-independent glucocorticoid increase |
|
Definition
| Adrenal adenoma/adenocarcinoma or increased consumption of glucocorticoids - adrenal gland atrophy, low plasma ACTH |
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|
Term
| ACTH-dependent increase glucocorticoids |
|
Definition
| Pituitary adenoma overproducing ACTH (Cushing disease) or paraneoplastic syndrome |
|
|
Term
| Cushing Syndrome symptoms |
|
Definition
| Increased protein metabolism, glucose mobilization, lipolysis, fat redeposition, immune suppression, striae rubrae, muscle weakness, tissue wasting, hyperglycemia not reversed by insulin |
|
|
Term
|
Definition
| Benign pituitary adenoma secreting ACTH - ACTH will be increased, excess glucocorticoids mainly |
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|
Term
|
Definition
| Hypersecreting adenoma, cancer patient with a 2nd benign tumor in lungs leading to ACTH increased secretion |
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|
Term
| Adrenal cortex adenoma affecting glucocorticoids |
|
Definition
| Negative feedback will still be intact so ACTH decreased but increased glucocorticoids |
|
|
Term
| Chronic glucocorticoid consumption |
|
Definition
| Negative feedback still intact so ACTH will be low but Cushing disease present due to increased glucocorticoids |
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|
Term
| Addison Disease - Primary insufficiency |
|
Definition
| Autoimmune deficiency, ACTH high due to reduced negative feedback; ACTH and alpha-MSH high so darker skin color; decreased hair growth in females (low androgens); glucocorticoid or aldosterone deficiency |
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|
Term
| Symptoms of glucocorticoid deficiency |
|
Definition
| Hypotension, hypoglycemia, fatigue |
|
|
Term
| Symptoms of aldosterone deficiency |
|
Definition
| Hyperkalemia, salt craving, altered cardiac function |
|
|
Term
| Addison disease - Secondary insufficiency |
|
Definition
| Pituitary ACTH deficiency, ACTH low, aldosterone not affected because under control of renin-angiotensin system - slow onset during stress leading to Addisonian crisis - need cortisol replacement and administration of fluids/glucose |
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|
Term
|
Definition
| Slow onset of adrenal cortex hormone insufficiency during time of stress; no glucocorticoids leads to hypotension, acute circulatory failure, need cortisol replacement and administration of fluids and glucose |
|
|
Term
|
Definition
| Conn's tumor secreting aldosterone leads to increased ECF volume, mild hypertension, hypokalemia, metabolic acidosis (H ions secreted) |
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|
Term
|
Definition
| Over-produced renin or stenosis of renal artery |
|
|
Term
| Adrenal medulla hormone storage |
|
Definition
| Norepinephrine and epinephrine are stored in chromaffin cells; 90% secrete Epinephrine, 10% secrete epinephrine; product released by ACh stimulation |
|
|
Term
| Chromaffin cell innervation |
|
Definition
| Multiple ganglionic cholinergic sympathetic nerve fibers into chromaffin cells; some release dopamine but not stored |
|
|
Term
| Synthesis of catecholamines progression |
|
Definition
Tyrosine --> Dopa (by tyrosine hydroxylase-rate-limiting)
Dopa --> Dopamine --> Norepinephrine --> Epinephrine |
|
|
Term
| Timing for Epi/Norepi effects |
|
Definition
| 10-30 seconds; weaker for few minutes; short half-life; no negative feedback regulation by hypothalamus of pituitary |
|
|
Term
| Hemodynamic effects of adrenal medulla hormones |
|
Definition
| Increase HR, cardiac output, BV tone, ECF volume, increase BP, dilate coronary vessels, contract skin vessels |
|
|
Term
| Metabolic effects of adrenal medulla hormones |
|
Definition
| Similar to glucocorticoids, stimulate glycogenolysis and gluconeogenesis; epinephrine is 10x more active at these processes |
|
|
Term
| Catecholamine degradation |
|
Definition
| MAO and COMT act on Epi and Norepi, eventually excreted as vanillylmandelic acid (VMA) |
|
|
Term
|
Definition
Benign tumor of chromaffin cells in adrenal medulla
Symptoms: sweat, pallor, palpitations, increase BP
Diagnosis: increased VMA in urine, treat with adrenergic a-receptor blockers until surgical resection |
|
|
Term
| Catecholamine underproduction |
|
Definition
| Rest of nervous system compensates but can reveal underlying autonomic dysfunction - postural hypotension, e.g. |
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|
Term
| Hormones secreted by beta cells of pancreas |
|
Definition
| C-peptide, amylin, insulin |
|
|
Term
| Blood supply of endocrine pancreas |
|
Definition
| Center of islet --> periphery --> capillary --> portal vein with secreted hormones (somatostatin thus will not inhibit insulin from beta cells) |
|
|
Term
| Endocrine pancreas innervation |
|
Definition
| Sympathetic and parasympathetic fibers with cholinergic stimulation to increase insulin secretion |
|
|
Term
|
Definition
| Secretion stimulated by gastric distension, vagal stimulation, nutrients; inhibited by hyperglycemia and somatostatin; activate Y4 receptor, reducing gastric emptying time, affects motility of upper intesine |
|
|
Term
|
Definition
| Co-secreted with insulin; post-prandial inhibition of glucagon, reduces gastric motility to help clear glucose from blood |
|
|
Term
| Why is measuring insulin unreliable? |
|
Definition
| 50-60% endogenous insulin immediately extracted by liver, some exogenous insulin as well; C-peptide is much more reliable |
|
|
Term
|
Definition
| Test for glycosylated hemoglobin, significantly increased in DM; glycosylation is irreversible and RBC live for 4 months so it is reliable indicator of average plasma glucose levels, try to keep <7% |
|
|
Term
| Insulin stimulation to oral glucose |
|
Definition
| Greater magnitude due to incretin effect (increased beta-cell sensitivity) - rapid and massive insulin increase |
|
|
Term
| Insulin stimulation to IV glucose |
|
Definition
| Biphasic - first rapid peak and slower more prolonged peak, no incretin; release all stored and then synthesize more; possible 3rd phase after 1.5-3 hours, can last up to 48 hours - diabetic has slow increase in insulin for many hours |
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|
Term
| Glucose entering beta cell of pancreas |
|
Definition
| GLUT2 receptor --> G6P by glucokinase --> oxidize to ATP --> close K channels --> depolarize --> open Ca channels --> exocytose granules with insulin |
|
|
Term
|
Definition
| Block K channels, control extent and timing of insulin release for individuals with Type 2 Diabetes Mellitus |
|
|
Term
| Insulin release stimulators |
|
Definition
| Hyperglycemia, amino acids, acute LCFA, incretin, gastrin, secretin, GIP, CCK, acetylcholine, sulfonylureas |
|
|
Term
| Insulin release inhibitors |
|
Definition
| Somatostatin, norepinephrine, epinephrine, long-term LCFA |
|
|
Term
| alpha-adrenoreceptor stimulation |
|
Definition
| Decrease cAMP, inhibit insulin release - stress for mobilizing glucose to produce energy |
|
|
Term
| beta-adrenoreceptor stimulation |
|
Definition
| Induce cAMP release to stimulate insulin release |
|
|
Term
| Glucagon release stimulators |
|
Definition
| Hypoglycemia, amino acids (protein meal), acetylcholine, norepinephrine, epinephrine |
|
|
Term
| Glucagon release inhibitors |
|
Definition
| Fatty acids, somatostatin, insulin |
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Term
| CHO vs. protein meal effect on I,G |
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Definition
CHO meal - high insulin, low glucagon
Protein meal - high insulin, high glucagon |
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Term
| Protein Tyrosine Phosphatase 1B |
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Definition
| deP'ylate and inactivate IR - insulin downregulates its own receptor by inducing this degradation - downregulation of IR leads to some reduced sensitivity to insulin seen in obesity and DM type II |
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Term
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Definition
| Help FA go from blood to adipose, target for insulin, leads to storage of FA, no lipolysis |
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Term
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Definition
| Primarily liver, also adipose, NOT MUSCLE; enter liver by portal vein; only acts on adipose at low insulin level |
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Term
| Stimulation of glucagon receptor on beta cell |
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Definition
| cAMP increases leading to insulin secretion from beta cell |
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Term
| Stimulation of insulin receptor on alpha cell |
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Definition
| cAMP decreases leading to inhibition/decrease in glucagon secretion |
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Term
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Definition
Hyperglycemia, polyuria, dehydration, polydipsia, eat more food, weightloss
Untreated: renal failure, erectile dysfunction, blindness, peripheral nerve lesions; increased rate of atherosclerosis |
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Term
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Definition
| Reduced/absent Insulin secretion; glucago predominates; immune-mediated destruction of beta cells (1A), lack of glucose can lead to ketoacidosis |
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Term
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Definition
| Normal insulin secretion in response to glucose --> reduced sensitivity of insulin receptor --> develop hyperglycemia --> pancreas increase insulin release --> reduced responsiveness to insulin (irreversible) |
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Term
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Definition
| Decreased glucose transport and metabolism in skeletal muscle and adipocytes, impaired suppression of hepatic glucose |
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Term
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Definition
| Common in DM Type I, rare in DM Type II; Type I generally progresses faster |
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Term
| Ca levels and binding amounts |
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Definition
| 9.0-10.5 mg/dL (2.3-2.6 mM) - 50% free ionized 40% protein-bound, 10% complex with anions - equilbrium |
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Term
| Effect of phosphate, citrate, acidosis, alkalosis on free Ca |
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Definition
More phosphate - less free Ca (crash injury)
More citrate - less free Ca (transfusion)
Acidosis - more free Ca
Alkalosis - less free Ca (hyperventilation) |
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Term
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Definition
| Nerve and muscle excitation, muscle contraction, enzyme function, bone mineral balance |
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Term
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Definition
| Bone structure, pH buffer |
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Term
| PTH vs. Vitamin D effect on Ca levels |
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Definition
PTH involved in short-term regulation
Vitamin D involved in long-term regulation |
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Term
| Ca and phosphate levels, what happens if increased |
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Definition
| Both near saturation point, increases can lead to precipitate or calcifications |
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Term
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Definition
| 84 aa hormone synthesized and secreted by chief cells in parathyroid gland (where oxyphils present too) |
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Term
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Definition
| 2-4 minutes; rapidly metabolized |
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Term
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Definition
| Secreted in non-mature form, further metabolism by liver to separate, N-terminus active - can go affect bone and kidney |
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Term
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Definition
| Increase bone resorption, increase renal Ca absorption at distal tubule, decrease phosphate resorption from proximal and distal tubule, increase synthesis of Vitamin D |
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Term
| Calcium Sensing Receptor (CASR) |
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Definition
| Detects reduction of circulating free Ca ions in plasma, leading to increased PTH secretion; mutations lead to diseases including familial hypocalciuric hypercalcemia |
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Term
| Metals with effects on PTH secretion |
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Definition
| Lithium stimulates PTH, Mg and Ca can stimulate or inhibit; Aluminum inhibits PTH |
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Term
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Definition
| GPCRs increasing cAMP, increase IP3, Ca - also bind PTHrP which can be secreted by some tumor cells to increase bone turnover to make from for metastasis |
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Term
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Definition
| Activate GPCR on osteoblast to produce RANK-L and IL-6 - stimulate resorption of osteoclasts; chronic elevation inhibits bone formation in osteoblasts; intermittent PTH stimulates osteoblasts to produce bone matrix |
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Term
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Definition
| Ca resorption on distal convoluted tubule, much faster increase of blood Ca than bone resorption but 90% Ca recovered in proximal convoluted tubule with no PTH |
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Term
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Definition
| Stimulate 1,25 hydroxylase to convert Vitamin D to most active metabolite |
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Term
| Vitamin D3 transformation |
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Definition
| Circulate bound to proteins, 1,25 hydroxylase in liver, and stored in adipose and muscle; further hydroxylated in kidney by 1,25 hydroxylase stimulated by PTH; active form is calcitriol |
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Term
| 1,25 hydroxylase stimulators |
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Definition
| PTH during hypocalcemia, estrogens, prolactin, GH |
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Term
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Definition
| steroid hormone with Type 2 receptor, 1000x greater affinity in active form, complex with Retinoic acid X receptor --> heterodimeric TF binding, VDRE includes calbindin |
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Term
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Definition
| Increase intestinal absorption of Ca and phosphate, stimulate maturation of osteoclast progenitor, inhibit PTH synthesis (negative feedback), weak positive reabsorption of Ca and phosphate in kidney |
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Term
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Definition
| Increase duodenum Ca absorption from 10% to 70% - direct opening of Ca channels on surface of intestinal cells |
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Term
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Definition
| Stimulate osteoblast cytokine production, osteoclast progenitors mature and enhance bone osteoclast degradation; increase osteoblast bone matrix formation (through osteopontin and osteocalcin) |
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Term
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Definition
| Stimulated by increased calcitriol, induces biodegradation of Vitamin D (negative feedback), synthesized by enhanced PTH |
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Term
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Definition
| 32 aa peptide made by parafollicular C-cells of thyroid to reduce Ca and phosphate levels in blood - uses same CASR to detect calcium levels |
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Term
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Definition
| Direct inhibition of osteoclast bone resorption, excrete Ca and phosphate from kidney, therapeutic use to fight osteoporosis; deficiency has no effect on Ca levels |
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Term
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Definition
| Reduced total bone mass which can be due to Ca diet deficiency, Vitamin C deficiency, reduced mechanical stress and advanced age |
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Term
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Definition
Often seen in primary hyperparathyroidism
Symptoms: Inotropic effect, HTN, mental confusion, salt and pepper skull |
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Term
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Definition
Hypoparathyroidism of crash injury (mass phosphate release)
Symptoms: hyperreflexia, muscle cramps, tingling, twitching (tetany)
Trousseau Sign and Chvostek Sign |
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Term
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Definition
| Keep BP cuff above arterial pressure for 3 minutes, generate contraction, opposition of thumb, contraction of joints if hypoparathyroidism |
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Term
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Definition
| Tap emergence of facial nerve at angle of jaw - look for contraction of same side in upper lips - test for hypoparathyroidism |
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