抄録
The localization of glutathione S-transferase P (GST-P) in postnatal rat liver was examined by an immunohistochemical technique. Dexamethasone (DEX) was injected intraperitoneally into postnatal rats at a dose of 2 μg/g body weight daily for 4 days. GST-P was detected only in the cytoplasm of epithelial cells of the interlobular bile ducts in the livers of 8-day-old rats that did not receive DEX-administration. In contrast, dispersed-positive hepatocytes were observed in the liver lobules of rats that were administered DEX from 4 days after birth. In these rats, GST-P was found in the cytoplasm of those hepatocytes and epithelial cells of the interlobular bile ducts. GST-P was observed only in the cytoplasm of epithelial cells of the interlobular bile ducts in the livers of 13-day-old rats that did not receive DEX-administration and those that began DEX-administration at 9 days. The immunoreactivity was stronger compared to the 8-day-old rats. These results indicate that DEX promotes the appearance of hepatocytes that contain the GST-P protein in early postnatal rat liver.
