Effect of nifedipine treatment (imprinting) of rat feti and newborns on the responsiveness of adult rat's uterus. Extension of the imprinting theory.

1. The uterus of adult progeny of rats treated with nifedipine during the late phase of pregnancy react in vitro to oxytocin less and the contractility of ones treated with higher dose (100 micrograms) disappears. 2. There is a more pronounced deficiency or lack of responsiveness in five week old animals treated with nifedipine neonatally. 3. The experiments demonstrate that perinatal imprinting can be developed not only on hormone receptors and enzymes but on ion (Ca2+) channels of the plasma membrane. Consideration of this fact might have an importance in clinical aspects too.