Evidence for pituitary regulation of placental lactogen in the rat

• DOI: 10.1677/joe.0.1070121
• Publication Date: 2008-12-11T22:45:06Z
• Authors: J. L. Voogt; P. L. Pakrasi; D. C. Johnson; S. K. Dey
• Keywords: Hypophysectomy; Placental lactogen; Median eminence

ABSTRACT The present studies examined whether the pituitary hormones, particularly prolactin, have any role in regulation of rat placental lactogen (rPL) secretion. Total rPL was measured using a lymphoma cell bioassay. Hypophysectomy on day 13 pregnancy increased total serum levels above those intact control rats and delayed for 3 days decline usually seen by 14. To test effect early hypophysectomy secretion, implantation model used. carried out 3, progesterone (2 mg) given daily until 8 oestrone (1·0 μg) 8. This initiated 9, which is 4 later than normal. Rats hypophysectomized had high (10–13 mg/l) 7 after initiation compared with values 2–3 mg/l, these remained raised duration experiment. Termination maintenance injections steroids did not affect several days, even though there fetal resorption. When pair anterior pituitaries transplanted under kidney capsule (day 9 development) still next days. However, unlike similarly treated receiving transplants, fell rapidly thereafter were only 5% animals 1 week later. Only either or doses normal pregnancies; other two groups steroid stopped 15 showed various degrees resorption abortion. It suggested that pituitary, possibly because its prolactin important J. Endocr. (1985) 107, 121–126