Table 2-2. HORMONES OF REPRODUCTION

Hormone			Chemical Nature			Sites of Synthesis			Target				Primary Actions

NEUROHORMONES:

GnRH			decapeptide			hypothalamus			anterior pituitary			FSH and LH production
PRF			TRH, serotonin			hypothalamus			anterior pituitary			PRL production
PIF			DA, GABA, GAP			hypothalamus			anterior pituitary			inhibit PRL secretion
oxytocin			nonapeptide			hypothalamus			uterus				smooth muscle contraction (labor)
											mammary gland			milk let-down
melatonin			indolamine			pineal gland			hypothalamus			seasonal control of GnRH

GONADOTROPINS:

FSH, LH			glycoprotein			anterior pituitary			gonad				steroidogenesis, gametogenesis
PMSG			glycoprotein			placenta				ovary				follicular growth, accessory CL formation
hCG			glycoprotein			placenta				ovary				luteal maintenance during early pregnancy
prolactin			protein				anterior pituitary			ovary				luteotropin
											mammary gland			milk synthesis
											hypothalamus			maternal behavior

GONADAL PROTEINS:

inhibin			glycoprotein			gonad				anterior pituitary			inhibit FSH secretion
relaxin			polypeptide			ovary, placenta			uterus, pelvis			mechanism of parturition
MIH			glycoprotein			fetal testis				Mullerian duct			duct regression (XY embryo)

STEROID HORMONES:

P4, T, E2			sex steroids			gonad, placenta			brain				feedback control of LH, sexual behavior
											reproductive tract			development, contractility
											mammary gland			development
											other				secondary sex characteristics
cortisol			glucocorticoid			adrenal cortex			placenta				induction of parturition