Nucleic acid metabolism of cells of the luminal epithelium and stroma of the rat uterus during early pregnancy.

The uptake of [5-3H]uridine into RNA and DNA of the cells of the uterine luminal epithelium, stroma and myometrium of the rat has been studied in early pregnancy using a technique for separation of the cell fractions before quantitative analysis. Comparisons of the metabolism between the pregnant and pseudopregnant horn of the unilaterally ovariectomized rat has shown that RNA and DNA synthesis are markedly increased by 04.00 hours on the morning of Day 5 in the pregnant horn. This increased metabolism occurs in all cell fractions and before the zona pellucida is shed. The results are discussed in relation to the onset of the decidual response.