Cellular localization of CYP3A proteins in various tissues from pilot whale (Globicephala melas)

The in situ expression of cytochrome P450 3A- (CYP3A) like proteins in hepa tic and extrahepatic tissues from a marine mammal, pilot whale (Globicephal a melas), was investigated. Polyclonal antibodies (PAb) raised against eith er rat CYP3A1 or trout CYP3A27 both recognized a microsomal protein band in liver, lung, kidney and heart. The protein band observed in liver and lung had slightly lower molecular weight than that observed in kidney and heart , suggesting the existence of two CYP3A forms in pilot whale. Immunohistoch emical analyses showed strong CYP3A-staining in hepatocytes, bile duct epit helial cells, bronchial epithelial cells? in primordial- and primary follic les and their surrounding zona glomerulosa. Moderate to strong CYP3A staini ng was seen in smooth muscle-like cells of large arteries and arterioles in all organs examined. Mild to moderate staining was evident in alveolar epi thelial cells and in kidney tubular epithelial cells. Weak staining was see n in glomerular epithelial cells and in seminiferous tubular epithelial cel ls. (C) 2000 Elsevier Science B.V. All rights reserved.