| Pituitary Hormones |
| Oxytocin | polypeptide of 9 amino acids
CYIQNCPLG (C's are disulfide bonded) | uterine contraction, causes milk ejection in lactating females, responds to suckling reflex and estradiol, lowers steroid synthesis in testes |
Vasopressin
(antidiuretic hormone, ADH) | polypeptide of 9 amino acids
CYFQNCPRG (C's are disulfide bonded) | responds to osmoreceptor which senses extracellular [Na+], blood pressure regulation, increases H2O readsorption from distal tubules in kidney |
| Melanocyte-stimulating hormones (MSH) | a polypeptide = 13 amino acids
b polypeptide = 18 amino acids
g polypeptide = 12 amino acids | pigmentation |
| Corticotropin (adrenocorticotropin, ACTH) | polypeptide = 39 amino acids | stimulates cells of adrenal gland to increase steroid synthesis and secretion |
| Lipotropin (LPH) | b polypeptide = 93 amino acids
g polypeptide = 60 amino acids | increases fatty acid release from adipocytes |
| Thyrotropin (thyroid-stimulating hormone, TSH) | 2 proteins: a is 96 amino acids; b is 112 | acts on thyroid follicle cells to stimulate throid hormone synthesis |
| Growth hormone (GH, or somatotropin) | protein of 191 amino acids | general anabolic stimulant, increases release of insulin-like growth factor-I (IGF-I), cell growth and bone sulfation |
| Prolactin (PRL) | protein of 197 amino acids | stimulates differentiation of secretory cells of mammary gland and stimulates milk synthesis |
| Luteinizing hormone (LH); human chorionic gonadotropin (hCG) is similar and produced in placenta | 2 proteins: a is 96 amino acids; b is 121 | increases ovarian progesterone synthesis, luteinization; acts on Leydig cells of testes to increase testosterone synthesis and release and increases interstitial cell development |
| Follicle-stimulating hormone (FSH) | 2 proteins: a is 96 amino acids; b is 120 | ovarian follicle development and ovulation, increases estrogen production; acts on Sertoli cells of semiferous tubule to increase spermatogenesis |
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| Hypothalamic Hormones |
| Corticotropin-releasing factor (CRF or CRH) | protein of 41 amino acids | acts on corticotrope to release ACTH and b-endorphin (lipotropin) |
| Gonadotropin-releasing factor (GnRF or GnRH) | polypeptide of 10 amino acids | acts on gonadotrope to release LH and FSH |
| Prolactin-releasing factor (PRF) | this may be TRH | acts on lactotrope to release prolactin |
| Prolactin-release inhibiting factor (PIF) | may be derived from GnRH precursor, 56 amino acids | acts on lactotrope to inhibit prolactin release |
| Growth hormone-releasing factor (GRF or GRH) | protein of 40 and 44 amino acids | stimulates GH secretion |
| Somatostatin (SIF, also called growth hormone-release inhibiting factor, GIF) | polypeptide of 14 and 28 amino acids | inhibits GH and TSH secretion |
| Thyrotropin-releasing factor (TRH or TRF) | polypeptide of 3 amino acids: EHP | stimulates TSH and prolactin secretion |
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| Thyroid Hormones |
| Thyroxine and triiodothyronine | iodinated dityrosin derivatives | responds to TSH and stimulates oxidations in many cells |
| Calcitonin | protein of 32 amino acids | produced in parafollicular C cells of the thyroid, regulation of Ca2+ and Pi metabolism |
| Calcitonin gene-related peptide (CGRP) | protein of 37 amino acids, product of the calcitonin gene derived by alternative splicing of the precursor mRNA in the brain | acts as a vasodilator |
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| Parathyroid Hormone |
| Parathyroid hormone (PTH) | protein of 84 amino acids | regulation of Ca2+ and Pi metabolism, stimulates bone resorption thus increasing serum [Ca2+], stimulates Pi secretion by kidneys |
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| Digestive Hormones |
| additional Table of gastrointestinal hormones |
| Gastrin | polypeptide of 17 amino acids | produced by stomach antrum, stimulates acid and pepsin secretion, also stimulates pancreatic secretions |
| Secretin | polypeptide of 27 amino acids | secreted from duodenum at pH values below 4.5, stimulates pancreatic acinar cells to release bicarbonate and H2O |
| Cholecystokinin (CCK) | polypeptide of 33 amino acids | stimulates gallbladder contraction and bile flow, increases secretion of digestive enzymes from pancreas |
| Motilin | polypeptide of 22 amino acids | controls gastrointestinal muscles |
| Vasoactive intestinal peptide (VIP) | polypeptide of 28 residues | produced by hypothalamus and GI tract, relaxes the GI, inhibits acid and pepsin secretion, acts as a neurotransmitter in peripheral autonomic nervous system, increases secretion of H2O and electrolytes from pancreas and gut |
| Gastri inhibitory peptide (GIP) | polypeptide of 43 amino acids | inhibits secretion of gastrin |
| Somatostain | 14 amino acid version | inhibits gastrin secretion from stomach and glucagon secretion from pancreas |
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| Pancreatic Hormones |
| Insulin | disulfide bonded dipeptide of 21 and 30 amino acids | produced by b-cells of the pancreas, increases glucose uptake and utilization, increases lipogenesis, general anabolic effects |
| Glucagon | polypeptide of 29 amino acids | produced by a-cells of the pancreas, increases lipid mobilization and glycogenolysis in order to increase blood glucose levels |
| Pancreatic polypeptide | polypeptide of 36 amino acids | increases glycogenolysis, regulation of gastrointestinal activity |
| Somatostatin | 14 amino acid version | inhibition of glucagon and somatotropin release |
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| Placental Hormones |
| Estrogens | steroids | maintenance of pregnancy |
| Progestins | steroids | mimic action of progesterone |
| Chorionic gonadotropin | 2 proteins: a is 96 amino acids; b is 147 | activity similar to LH |
| Placental lactogen | protein of 191 amino acids | acts like prolactin and GH |
| Relaxin | 2 proteins of 22 and 32 amino acids | produced in ovarian corpus luteum, inhibits myometrial contractions, secretion increases durin gestation |
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| Gonadal Hormones |
| Estrogens (ovarian) | steroids; estradiol and estrone | maturation and function of female secondary sex organs |
| Progestins (ovarian) | steroid; progesterone | implantation of ovum and maintenance of pregnancy |
| Androgens (testicular) | steroid; testosterone | maturation and function of male secondary sex organs |
| Inhibins A and B | 1 protein (a is 134 amino acids; b is 115 and 116 amino acids | inhibition of FSH secretion |
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| Adrenal Cortical Hormones |
| Glucocorticoids | steroids; cortisol and corticosterone | diverse effects on inflammation and protein synthesis |
| Mineralocorticoids | steroids; aldosterone | maintenance of salt balance |
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| Adrenal Medullary Hormones |
| Epinephrine (adrenalin) | derived from tyrosine | glycogenolysis, lipid mobilization, smooth muscle contraction, cardiac function |
| Norepinephrine (noradrenalin) | tyrosine derivative | lipid mobilization, arteriole contraction |
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| Liver Hormones |
| Angiotensin II | polypeptide of 8 amino acids derived from angiotensinogen (present in the a2-globin fraction of plasma) which is cleaved by the kidney enzyme renin to give the decapeptide, angiotensin I, the C-terminal 2 amino acids are then released (by action of angiotensin-converting enzyme, ACE) to yield angiotensin II | responsible for essential hypertension through stimulated synthesis and release of aldosterone from adrenal cells |
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| Kidney Hormones |
Calcitriol
[1,25-(OH)2-vitamin D3] | derived from 7-dehydrocholesterol | responsible for maintenance of calcium and phosphorous hoemostasis, increases intestinal Ca2+ uptake, regulates bone mineralization |
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| Cardiac Hormones |
| Atrial natriuretic peptide (ANP) | several active peptides cleaved from a 126 amino acid precursor | released from heart atria in response to hypovolemia, acts on outer adrenal cells to decrease aldosterone production; smooth muscle relaxation |
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| Pineal Hormones |
| Melatonin | N-acetyl-5-methoxytryptamine | regulation of circadian rhythms |