Influence of endogenous growth hormone-releasing factor (GRF) on the secretion of GH during the perinatal period in the rat.
Passive immunization of pregnant rats with a specific antiserum to rat GRF (GRF-AS) is followed by a decrease in fetal serum GH on the 19th day of gestation. A significant reduction in serum GH is still observed in older fetuses and newborn rats. Pituitary GH content increases in 19- and 20-day-old fetuses after GRF-AS administration to their mothers. These results suggest that endogenous fetal hypothalamic GRF (or placenta GRF) play a physiological role in the secretion of pituitary GH as early as the 19th day of fetal life and may be responsible for the peak of GH release that occurs in fetuses at the end of gestation.
D000375:Aging; D000818:Animals; D005260:Female; D005312:Fetal Blood / Q000032:analysis; D005333:Fetus; D005865:Gestational Age; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000276:immunology / Q000502:physiology*; D007106:Immune Sera; D007116:Immunization, Passive; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains
D007106:Immune Sera; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone