title: Endocrine regulation of fetal development and its relation to parturition in the rhesus monkey.
abstract: Rhesus monkey fetuses were surgically prosencephalectomized (Type 2) or functionally hypophysectomized (Type 1) at 75 days gestation, then returned to the uterus until elective Caesarean section on day 145--150 (term 167 days). Deprivation of fetal hypothalamic releasing factors in Type 2 and fetal pituitary tropic hormones in Type 1 significantly delayed the ontogeny and functional development of fetal endocrine tissues. Bone ossification and growth were significantly retarded in Type 1 only, not in Type 2. In Type 1 the body and all organs except the endocrine glands were about half normal weight. The adrenals, thyroids, ovaries and testes were histologically abnormal and about one-tenth normal weight. Non-endocrine organs were histologically similar to 110-130-day fetuses. Thyroxine (T4) concentrations were significantly depressed in Type 1 fetal and maternal plasma at Caesarean section but normal in Type 2. Cortisol concentrations were normal in Type 1 fetal and maternal plasma. Types 1 and 2 plasma oestradiol concentrations were significantly lower in mothers but normal in fetuses. Type 1 placentas produced significantly less progesterone in vitro than normal. Fetal endocrine autonomy is indicated (thyrotropin-releasing factor excepted). Many of the hypothalamic and anterior pituitary hormones do not pass in effective amounts from mother to fetus. Fetal endocrine autonomy is a prerequisite for the control of both development and parturition.
mesh_terms: D000311:Adrenal Glands / Q000196:embryology; D000818:Animals; D004702:Endocrine Glands / Q000196:embryology*; D004967:Estrogens / Q000378:metabolism; D005260:Female; D005333:Fetus / Q000502:physiology*; D000882:Haplorhini; D006728:Hormones / Q000502:physiology*; D006854:Hydrocortisone / Q000378:metabolism; D007743:Labor, Obstetric; D008251:Macaca / Q000196:embryology*; D008253:Macaca mulatta / Q000196:embryology*; D008431:Maternal-Fetal Exchange; D010902:Pituitary Gland / Q000196:embryology / Q000502:physiology; D010907:Pituitary Hormones / Q000502:physiology; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism; D051381:Rats; D012863:Skeleton / Q000196:embryology; D013961:Thyroid Gland / Q000196:embryology
chemical_list: D004967:Estrogens; D006728:Hormones; D010907:Pituitary Hormones; D011374:Progesterone; D006854:Hydrocortisone