[Cellular growth of uterus, placenta and fetus during chronic maternal caloric restriction in rats]

Wistar strain female rats were maintained with restricted amounts of 25% casein diet before and during pregnancy. Uteri, placentas and fetuses were removed from the rats beginning the 14th day of conception and continuing it up to the 20th day. Tissues were analyzed in regard to weight, nucleic acids and protein content. A 25% food restriction decreased dramatically the uterine, placental and fetal size as well as DNA content. RNA and protein content were also found diminished, but it must be emphasized that these findings were less important than the DNA content reduction observed. This is the reason why RNA/DNA and protein/DNA ratios were markedly elevated in regard to control values. Cellular changes observed in the reproductive organs and their relationships with fetal growth failure, induced by maternal dietary modification, are discussed.