Studies on the role of zinc in parturition in the rat

Abstract

1. Pregnant rats were fed either low (<1 p.p.m.) Zn or control (40p.p.m. Zn) diets from day 10 of gestation. They were killed at intervals during the last 96h preceding the normal time for onset of parturition, and differences in plasma progesterone, oestradiol-17, and ovarian 20a-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 20a-hydroxysteroid dehydrogenase activity was delayed by about 8h by Zn deficiency. This delay was not observed if prostaglandin F2. was injected previously. 5. The results suggest a Zn-dependent step(s) in uterine synthesis and/or release of prostanoids.Zinc was first reported to be required for normal parturition in the rat by Apgar (1968a). Female rats fed a diet containing 1 p.p.m. or less of Zn beginning on the first day after mating displayed loss of appetite and lethargy. Harderian-gland pigment often accumulated on the face and paws. Delivery was difficult and prolonged and accompanied by excessive bleeding, and most of the neonates were abandoned and placentae were left unconsumed. Further studies (Apgar, 1968b(Apgar, , 1970(Apgar, , 1972(Apgar, , 1973(Apgar, , 1975(Apgar, , 1976(Apgar, , 1977aGombe et al., 1973) showed that such effects were relatively specific to Zn deficiency and were not induced by restriction either of total food intake (pair-feeding) or

Micronutrient deficiencies in maternity and child health: a review of environmental and social context and implications for Malawi

“…Zinc deficiencies in pregnancy for women deprived of animal foods or easily absorbed cereals have risk of babies that are light for their gestational age, for whom poor growth in infancy continues. Zinc deficiency may also be responsible for poor functioning of the human uterus in labour, as is the case for the rat (Bunce et al 1983), albeit experimentally. There is a research opportunity for investigation into this aspect of human labour, taking account of pregnancy diets, maternal nutrition and foetal weights.…”

Influences of zinc on fertilisation and development of bovine oocytes in vitro

“…Zinc is important in all biological systems. In vivo and in vitro reproductive studies have shown that zinc is essential for spermatogenesis (Abbasi et al, 1980;Nishi et al, 1984), testosterone production (Leake et al, 1984;Favier, 1992b), as a decapacitation factor (Aonuma et al, 1981;Andrews et al, 1989), for conception (Golub et al, 1984), for blastocyst development and implantation (Hurley & Shrader, 1975;Record et al, 1985;Peters et al, 1991), organogenesis (Hurley (Swenerton, 1966), fetal growth (Prasad et al, 1961;Eriksson, 1984) and parturition (Bunce et al, 1983;Hambridge et al, 1986). The purpose of this study was to investigate the effects of different concentrations of zinc on major components of the bovine IVMFC model.…”

Effects of acute and chronic prednisolone treatment on serum zinc levels in rats with adjuvant arthritis

“…They were kept alone in makrolon cages on a 12 h light-dark cycle at constant temperature (20-22 ~ and humidity (40-60%) and had free access to food and desionised water. Solid food was a complete maintenance diet from the Usine d'alimentation rationelle, Villemoisson, France (ref: A04), containing 85 mg zinc/kg, and representing for the animals a daily zinc intake of between 1.7 and 2.1 mg, which is considered as adequate [29,30]. Contribution of water to zinc nutriture is negligible.…”