Studies on the role of zinc in parturition in the rat.
1. Pregnant rats were fed either low (less than 1 p.p.m.) Zn or control (40 p.p.m. Zn) diets from day 10 of gestation. They were killed at intervals during the last 96 h preceding the normal time for onset of parturition, and differences in plasma progesterone, oestradiol-17 beta and ovarian 20 alpha-hydroxysteroid dehydrogenase were assessed. 2. Gestation was prolonged in Zn-deficient rats. 3. Although the preparturient decline in plasma progesterone began at the same time in all groups, at term, plasma progesterone concentration in Zn-deficient rats remained significantly higher than in normal females. 4. Induction of ovarian 20 alpha-hydroxysteroid dehydrogenase activity was delayed by about 8 h by Zn deficiency. This delay was not observed if prostaglandin F2 alpha was injected previously. 5. The results suggest a Zn-dependent step(s) in uterine synthesis and/or release of prostanoids.
D015089:20-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D043607:20-alpha-Hydroxysteroid Dehydrogenase; D000818:Animals; D015237:Dinoprost; D004435:Eating; D004492:Edetic Acid / Q000494:pharmacology; D005260:Female; D005333:Fetus / Q000502:physiology; D005865:Gestational Age; D012739:Gonadal Steroid Hormones / Q000097:blood; D006128:Growth; D007743:Labor, Obstetric; D010053:Ovary / Q000187:drug effects / Q000201:enzymology; D011247:Pregnancy; D011460:Prostaglandins F / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D015032:Zinc / Q000097:blood / Q000172:deficiency / Q000378:metabolism*
D012739:Gonadal Steroid Hormones; D011460:Prostaglandins F; D004492:Edetic Acid; D015237:Dinoprost; D015089:20-Hydroxysteroid Dehydrogenases; D043607:20-alpha-Hydroxysteroid Dehydrogenase; D015032:Zinc