Effect of gestational and lactational exposure to lead and/or cadmium on reproductive performance and hepatic oestradiol metabolising enzymes.
Adult female rats were treated subcutaneously (0.05 mg/kg body wt./day) with lead acetate and cadmium acetate separately and in combination during the gestational and lactational periods with a pre-exposure before mating. No change in the reproductive cyclicity was observed in any of the treated groups. The number of pregnancies was similar in all groups and no effect was observed on reproductive performance. The litter size, placental weights, pup weights, pup liver weights, maternal weights or maternal liver weights did not differ significantly. The activities of hepatic steroid metabolising enzyme 17-beta-hydroxy steroid oxidoreductase and of UDP glucoronyl transferase were decreased and the hepatic cytochrome P450 (CYP450) content was reduced by the metal exposure. Hepatic DNA and glycogen content were decreased in the cadmium and the combined treated groups in both lactating mother and pups at post-natal day 21 (PND 21). Lead and cadmium accumulated in the liver of the metal treated pregnant and lactating rats. The accumulation of the metals was also observed in foetal and pups (PND 21). Hepatic zinc content was increased in the cadmium and the combined treated pregnant and lactating mothers whereas foetal and neonatal livers showed a decrease in the zinc as compared to control. The results of the study indicate that despite the ability of lead and cadmium to alter various biochemical parameters the effect in the liver is not intensified at combined exposure to both lead and cadmium. The observed biochemical alterations in the liver of rats co-exposed to lead and cadmium may result from an independent effect of lead and/or cadmium and also from their interaction. However, these results suggest that when lead and cadmium are administered together in similar concentrations, the major effects are mediated by cadmium.
Pillai
Anilkumar
A
Department of Biochemistry, Faculty of Science, M.S. University of Baroda, Vadodara, Gujarat 390002, India.
Gupta
Sarita
S
D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002104:Cadmium / Q000493:pharmacokinetics / Q000633:toxicity*; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D014453:Glucuronosyltransferase / Q000378:metabolism; D007774:Lactation / Q000502:physiology*; D007854:Lead / Q000493:pharmacokinetics / Q000633:toxicity*; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008112:Liver Glycogen / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D012098:Reproduction / Q000187:drug effects*; D015032:Zinc / Q000493:pharmacokinetics
D008112:Liver Glycogen; D002104:Cadmium; D007854:Lead; D004958:Estradiol; D012313:RNA; D004247:DNA; D015067:17-Hydroxysteroid Dehydrogenases; D014453:Glucuronosyltransferase; D015032:Zinc