Down-Regulation ofmdr1bmRNA Expression in the Kidneys of Mice Following Maternal Exposure to Tributyltin Chloride

We investigated the change in renal mdr1b mRNA expression in offspring exposed to tributyltin chloride (TBTC) via the placenta and lactation or via lactation, using the real-time reverse transcription-polymerase chain reaction. Pregnant ICR mice were given water containing TBTC (0, 15, and 50 microg/ml) ad libitum from the start of pregnancy to weaning or from parturition to weaning. Exposure via the placenta and lactation significantly reduced the renal mdr1b level in offspring. Exposure to TBTC through the mother might impair the exclusion system of toxic compounds in offspring.