Effect of Maternal Protein Deficiency on Cellular Development in the Fetal Rat

Abstract

The effects of maternal protein deficiency in rats on cell number and size in the offspring were investigated. Pregnant rats were fed a diet containing 30% or 6% casein. DNA, RNA, and total protein were determined in whole carcasses of 16-day-old fetuses and in liver, kidney, heart, thymus, brain, and carcass of 18- and 20-day-old fetuses and newborn young. Young of protein-deficient females had smaller organ and carcass weights at all ages studied. Total DNA was significantly decreased in livers of 18-day fetuses and in all tissues studied of 20-day fetuses and newborn young. Total protein was significantly reduced in liver and carcass at each age and in the other organs, beginning at 20 days. Total RNA was reduced in all tissues except brain beginning at 20 days. Weight/DNA ratio in the livers of newborn protein-deficient animals was increased. There were no differences in weight/DNA ratios in other organs, or in protein/DNA or RNA/DNA ratios. The data indicated that the effect of maternal protein deficiency on body and organ size was primarily a result of a decrease in cell number in the last 4 days of gestation.