Studies of the uptake and distribution of inulin and alpha-aminoisobutyric acid after intraamniotic injection in the guinea pig.

Pregnant guinea pigs were given intraamniotic injection of 14C-alpha-aminoisobutyric acid and 3H-inulin. Both substances were taken up by the fetus in different concentrations. High levels of alpha-amino-isobutyric acid were found in the placenta, liver, and serum. Inulin on the other hand, being a macro-molecule distributed by diffusion in the extracellular space, was found in high concentrations in the small intestine and in the placenta. Thus the main pathway for transferring nutrient substances from the amniotic fluid to the fetus would seem to be the gastro-intestinal tract. Thus supplementary nutrition of the fetus by the intraamniotic injection of nutrients is a possibility.