The acid ethanol extractable insulin content of pancreases from thirty-seven infants and three early fetuses of diabetic and control mothers has been measured and their islet cell histology was studied. In general there was good agreement between these two parameters.
Pancreatic insulin could be detected in one of two twelve-week old fetuses examined and in the pancreas of a fourteen-week old fetus of a diabetic mother. The remaining thirty-seven pancreases were obtained from fetuses of gestational age twenty weeks to term, nine of whom were offspring of diabetic mothers. The latter contained more insulin than the corresponding control group. The possible mechanisms are discussed; the hyperglycemic hypothesis is favored.