Background: To evaluate if the renotrophic factor can pass through the placenta and act on the fetal kidney.
Material and methods: Twenty pregnant rats were divided into 4 groups of 5 animals: 1-control; 2-sham operated animals; 3-right nephfrectomy; 4-right nephrectomy--left polar nephrectomy. All rats were operated on during the 14 or 15 day of pregnancy. Maternal weight, serum urea and creatinine, number of fetal rats, fetal body and renal weight; DNA, RNA, protein and the amount of water in fetal kidneys were evaluated.
Results: Fetal kidneys showed a fall in weight in groups 3 and 4. In these groups tissue water concentration was lesser than groups 1 and 2. Fetal kidneys amounts of DNA, RNA and protein were similar in all groups.
Conclusions: This study suggest that renotrophin could be a multifactorial system that can cross the placenta. The fall in renal fetal weight following maternal nephrectomy was consequent to a lesser tissue water content. Hypoplasia or hypotrophy did not play a role in this event. However, the fall in fetal kidney water was independent of the amount of maternal renal tissue that was removed.