Loeper J, Descatoire V, Maurice M, Beaune P, Belghiti J, Houssin D, Ballet F, Feldmann G, Guengerich F P, Pessayre D
Institut National de la Santé et de la Recherche Médicale: Unit 24, Clichy, France.
Gastroenterology. 1993 Jan;104(1):203-16. doi: 10.1016/0016-5085(93)90853-5.
Anti-cytochrome P-450 autoantibodies are present in several forms of autoimmune hepatitis. The possibility that cytochromes P-450 are present in the plasma membrane of human hepatocytes was examined.
(1) Plasma membranes with microsomal contamination < 1%, as judged from the activities of glucose-6-phosphatase and NADH-cytochrome c reductase, were prepared. (2) After exposure of uncut, fixed hepatocytes to antibodies, immunofluorescence and immunoperoxidase studies were performed.
(1) The specific content of cytochrome P-450 in plasma membrane was 9% of that in microsomes. Plasma membranes showed NADPH-cytochrome c reductase and mono-oxygenase activities; immunoblots showed the presence of cytochromes P-450 1A2, 2C, 2D6, 2E1, and 3A4; cytochromes P-450 1A2, 2D6, and 2C were also recognized by anti-liver microsome and anti-liver/kidney microsome type 1 and type 2 autoantibodies, respectively. (2) Immunofluorescence and immunoperoxidase labeling of the plasma membrane was observed with the three auto-antibodies and with anti-cytochrome P-450 1A2, 2C, 2E1, or 3A4.
It is concluded that cytochromes P-450 are present and functional in the plasma membrane of human hepatocytes and that anti-cytochrome P-450 autoantibodies recognize epitopes expressed on the outer surface.
抗细胞色素P - 450自身抗体存在于多种形式的自身免疫性肝炎中。本研究检测了细胞色素P - 450是否存在于人类肝细胞的质膜中。
（1）制备葡萄糖-6-磷酸酶和NADH-细胞色素c还原酶活性显示微粒体污染<1%的质膜。（2）将未切割的固定肝细胞与抗体孵育后，进行免疫荧光和免疫过氧化物酶研究。
（1）质膜中细胞色素P - 450的比含量为微粒体中的9%。质膜显示NADPH-细胞色素c还原酶和单加氧酶活性；免疫印迹显示存在细胞色素P - 450 1A2、2C、2D6、2E1和3A4；细胞色素P - 450 1A2、2D6和2C分别也被抗肝微粒体抗体和抗肝/肾微粒体1型和2型自身抗体识别。（2）用三种自身抗体以及抗细胞色素P - 450 1A2、2C、2E1或3A4观察到质膜的免疫荧光和免疫过氧化物酶标记。
得出结论，细胞色素P - 450存在于人类肝细胞的质膜中且具有功能，抗细胞色素P - 450自身抗体识别在外表面表达的表位。
