Ornithine decarboxylase activity and concentrations of polyamines in embryos of diabetic rats.

Previous studies have demonstrated high concentrations of polyamines in neoplastic tissue and embryos and these compounds are therefore believed to play a role in cellular growth and embryonic development. Maternal diabetes causes embryonic dysmorphogenesis and alterations in embryonic polyamine concentrations may contribute to this process. In the present study we have measured the contents of DNA, putrescine, spermidine and spermine in embryos on days 10 and 11 of gestation in normal and diabetic rats. We also estimated the activity of ornithine decarboxylase (ODC) in embryos on days 9-11. We found that maternal diabetes causes delayed growth as reflected by decreased content of DNA on day 11 in the embryos of the diabetic group. Both the polyamine content and ODC activity were altered in the embryos of diabetic rats. Thus, the polyamines were increased on day 10 and decreased on day 11, and the ODC activity was decreased in a down-regulated manner in day-10 embryos of the diabetic rats. These findings suggest that polyamine metabolism is involved in the dysmorphogenesis of diabetic pregnancy.