Effect of insulin on growth and biochemical composition of the rat fetus.

Abstract

Rat fetuses were given daily injections of insulin for 3 days and were sacrificed 24 hr after the third injection. Injections started at 171/2, 181/2 or 191/2 days post coitum (p.c.); hence the fetuses were removed at 201/2, 211/2 or 221/2 days p.c. In the fetuses born alive, fresh weight, dry weight and the total amount of nitrogen and lipids were determined. In fetuses sacrificed at 201/2 days p.c, insulin injections had no significant effect on these values. On the contrary, in fetuses taken just before delivery at 211/2 days p.c, and particularly in post-mature fetuses taken at 221/2 days p.c, fresh weight, dry weight, the total amount of lipids and nitrogen and the lipids/nitrogen ratio were higher in the insulintreated animals than in the controls; the differences between the 2 groups were statistically significant. The effect of insulin is compared to the clinical abnormalities observed in infants born to diabetic mothers. Experimental data, concerning the offspring of female rats made diabetic by pancreatectomy or alloxan injections, are also considered. (Endocrinology 81: 1419, 1967)