Hormone
- hormone
- substance synthesized in one organ & transport by circulatory system to act on other tissue
- cholesterol derived
- glucocorticoid
- mineralocorticoid
- estrogen
- progestin
- synthesized in final form & secrete immediately
- steroid
- progesterone - precursor of mineralocorticoid, glucocorticoid, androgen
- polypeptide
- ACTH, TRH, PTH, GH
- agonist - fool responder into thinking a hormone has bound
- antagonist - prevent bind
- Class
- chemical composition
- solubility properties
- location of receptors
- nature of signal produced
- G1 + ic receptor
- steroid hormone enter cell by simple diffusion
- TH facilitated diffusion
- androgen, calcitriol, estrogen, progestin, retinoic acid, glucocorticoid, mineralocorticoid, TH
- lipophilic
- receptor in cytoplasm or nucleus
- G2 + cell surface receptor
- 2nd mssger
- cAMp - a2 adrenergic catecholamine, b adrenergic catecholamine, ACTH, ADH, calcitonin, FSH, LH, TSH, glucagon, somatostatin
- cGMP - atrial natriuretic factor, NO - potent vasodilator
- made from GTP by gaunylylcyclase
- inhibitor: sildenafil (viagra)
- Ca/PI - acetylcholine, angiotensin, gastrin, TRH, oxytocin, ADH, PDGF
- hormone epinephrine + receptor + G protein 7 span domain - Ga GDP +P to GTP, Gb & y separated
- activate adenylyl cyclase
- ATP to cAMP
- activate PK
- PKA heterotetramer
- 2 regulatory, 2 catalytic
- 4cAMP + R2C2 = R2(4cAMP) + 2C
- R2C2 not active catalytic
- C active catalyze transfer of gamma phosphate of ATP to serine or threonine
- phosphatase -P
- phosphodiesterase convert cAMP to 5' AMP
- caffeine - methylated xanthine, increase cAMP, prolong hormone action
- activate protein
- G protein signaling disrupted
- deficient or excessive G protein signal transmission
- decrease G protein
- night blindness - mutation in Ga
- pseudohypoparathyroidism - genetic loss of Ga
- whooping cough
- increase G protein
- testotoxicosis - mutation in LH receptor - over produce testosterone
- vibrio cholera - + ADP ribose to Ga - fatal diarrhea
- hormone receptor
- 10^-18~-9 in ECF
- recognition domain - + hormone ligand
- fx domain - generate signal
- protein
- insulin receptor - heterotetramer a2 + insulin, b2 span membrane + tyrosine kinase activity
- steps
- recognition of stimulus
- hormone release
- signal generation
- autocrine signal - same cell
- endocrine signal - neural, paracrine
- synaptic signal - neuron, muscle
- paracrine signal - c-c
- effects
- G1 gene transcription
- G2 gene transcription, channels transporters, protein translocation, protein modification
- signal transduction
- receptor + ligand
- 2nd mssger - aa, peptide, FA, lipid
- hydrophilic mssger + CM receptor
- hydrophobic mssger + IC receptor
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