[Clinico-pathological studies of cytochrome P-450 on human hepatic disorders]

Immunohistochemical examinations were carried out for the study of cytochrome P-450 implication in the human hepatic disorders. An isozyme of human hepatic P-450 (P-450-HM1) with the m.w. of 51,000 was purified from human autopsied liver. Antibody against P-450-HM1 was prepared in rabbits, of which specificity was confirmed by Western blot. Eighty-three livers (27 autopsies and 56 biopsies, M:F = 63:20), which were either normal or of various hepatic disorders such as acute or chronic hepatitis, cirrhosis and hepatocellular carcinomas, were examined by the method of avidin-biotin-complex technique. It was revealed that immunoreactive hepatocytes were diffused throughout the lobule of the fetal liver. In the normal livers as well as those of acute and chronic hepatitis, positive hepatocytes were found in the centrilobular zone. Three of the 4 cases treated with beta-interferon showed faint staining; and the presence of positive individual hepatocytes was considered to be induced by steroid therapy. In the livers with chronic hepatitis and cirrhosis, hepatocytes near the perifibrous region and those trapped in the portal triad by thin fibrous connective tissue, as well as in the regenerating nodules, were strongly stained, which indicate that P-450-HM1 is expressed in the regenerating hepatocytes. Hepatocellular carcinomas, however, were devoid of immunohistochemistry. From these results, the antibody might be a useful tool for differentiating regenerating nodule from hepatocellular carcinoma.