Hormonal regulation of casein synthesis at the end of pregnancy.
Ovariectomy or ovariohysterectomy on day 18 of pregnancy augmented mammary beta-casein content 28 h later. Progesterone injected immediately and 12 h after ovariectomy showed a clear inhibitory effect on casein synthesis. Estrogen induced a significant increase in mammary beta-casein content when injected 12 h after surgery. Treatment with CB-154 to prevent prolactin release did not affect the increase of casein induced by ovariectomy. When CB-154 was injected to ovariohysterectomized pregnant rats, significant reduction of casein synthesis was obtained. According to these findings, rat placental lactogen in the absence of prolactin and progesterone induces beta-casein synthesis. Therefore prolactin, ovarian and placental hormones interplay at the end of pregnancy for full expression of the mammary gland genome.
D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology; D002364:Caseins / Q000096:biosynthesis*; D002369:Castration; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation; D007044:Hysterectomy; D010053:Ovary / Q000502:physiology; D010928:Placental Lactogen / Q000502:physiology*; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000502:physiology*; D011388:Prolactin / Q000378:metabolism / Q000502:physiology*; D051381:Rats
D002364:Caseins; D004967:Estrogens; D001971:Bromocriptine; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D010928:Placental Lactogen