Culture in vitro as a means of analysing the effect of maternal diabetes on embryonic development in rats.

Rodents have been used by many investigators for studies of the effects that maternal diabetes during pregnancy may have on developing fetuses. In Wistar rats, the induction of mild chronic diabetes at the onset of pregnancy by alloxan or streptozotocin results in abnormalities of the nervous system and the heart, recognized in embryos at 11--13 days' gestation. Thus, early organogenesis is evidently affected in these embryos. With a method which enables rat embryos to be cultured in vitro in serum for the period of their early organogenesis, the growth and differentiation of embryos from normal and from diabetic rats can be observed in some detail. It is also possible to compare the effects of normal and of diabetic maternal serum on their development. The results reported here show that embryos from diabetic animals are more likely to be retarded or abnormal than those from non-diabetic animals when cultured in identical serum. The development of both types of embryo is more successful in diabetic than in non-diabetic serum, however, possibly because of the higher glucose content of diabetic serum. Cultures of fetal organs may also be used as test systems for the effects of diabetic maternal serum. Sacral vertebrae, some of which fail to ossify in fetuses from daibetic rats, are now being grown in media containing diabetic serum. It is planned to test the effects of insulin on these cultures.