Progestin production by the ovary of the testosterone-sterilized rat treated with an ovulatory dose of LH, and the normal, proestrous rat

V. Cortes, J. A. Mc cracken, C. W. Lloyd, Judith Weisz

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13 Scopus citations

Abstract

Follicular cystic ovaries of 150-day-old testosterone-sterilized rats were used to study the ability of nonluteal tissue to produce progestins when stimulated with an ovulatory dose of LH. Three parameters were studied: A) the incorporation of 14C-acetate into progesterone (P) and 20α-hydroxypregn-4-en-3-one (20α- OHP) during a 6-hr incubation of ovaries obtained 2, 6, 10, 14 and 18 hr after the LH injection, b) the concentration of P and 20α-OHP in the ovarian venous blood 2, 6, 10, 14 and 18 hr after the LH injection, and c) the activity of Δ5-3β-ol steroid dehydrogenase and 20α-hydroxysteroid dehydrogenase by histochemistry. The concentrations of P and 20α-OHP in the ovarian venous blood were also measured in normal rats in proestrus. Ovulation occurred in the testosterone-sterilized rats between the 10th and 14th hr after the injection of LH. In vitro there was no detectable incorporation of radioactivity into P or 20α-OHP by the polycystic ovaries before LH treatment. Radioactive P and 20α-P were obtained in all incubations obtained from the testosterone- sterilized rats 6, 10, 14 and 18 hr after the LH injection. In the ovarian venous blood of the untreated testosterone-sterilized rats, P and 20α-OHP were <0.1 μg/100 ml. They rose after LH, reached a maximum (P, 61.6; 20α-OHP, 25.5 μg/100 ml) 10 hr after LH and fell to low levels after ovulation. Progesterone was higher than 20α-OHP except at 18 hr after the injection of LH. In ovarian venous blood of normal rats there was a rise of P beginning in the afternoon of proestrus. Peak levels were reached at 2200 hr. Quantitatively, this progesterone peak resembled the P surge induced in the testosterone-sterilized rats by LH treatment. In the normal there were 2 peaks of 10α-OHP, one before and one after the P surge. Levels of 20α-OHP were always higher than those of P. There was no evidence of luteinization or changes in 3β-or 20α-hydroxysteroid dehydrogenases in the follicular cystic ovaries after LH treatment and before ovulation.

Original languageEnglish (US)
Pages (from-to)878-885
Number of pages8
JournalEndocrinology
Volume89
Issue number3
DOIs
StatePublished - Sep 1971

All Science Journal Classification (ASJC) codes

  • Endocrinology

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