Effect of Protein Deficiency during Gestation on Postnatal Cellular Development in the Young Rat

Abstract

The effects of maternal protein deficit during pregnancy in rats on cell number and cell size in the organs of the progeny in the suckling period were studied. The effects of increased postnatal feeding of these progeny were also investigated. Pregnant rats were fed a diet containing 30% or 6% casein. Postnatally, young were suckled by nondeficient mothers in litters of eight until weaning or in litters which were cut to four young beginning at the age of 7 days. DNA, RNA, and total protein were determined in liver, kidney, heart, thymus, and brain of male young at 7, 14, and 21 days of age. Young of protein-deficient dams suckled in litters of eight had significantly decreased organ weights, DNA, total protein, and total RNA which persisted from birth but did not become more severe. When litters were cut to four in order to increase food intake, livers, kidneys, and hearts increased in weight and cells increased in size, but there were no significant changes in the numbers of cells in these organs. In the thymus, however, the number of cells increased, and cells decreased in size, while in the brain, the weight, DNA content, and apparent cell size were unaffected. The reduction of litter size had no effect on the deficit in cell population in any of the organs studied.