쥐 담즙울체간에서의 Arylamine N-Methyltransferase의 활성도

Abstract

Changes of arylamine N-methyltransferase (AMT) activity in cholestatic rat liver were studied. Cytosolic, mitochondrial and microsomal AMT activities were determined in cholestatic rat livers induced by common bile duct (CBD) ligation over a period of forty two days. The enzyme activity in serum, and Km and Vmax values of the hepatic enzyme were also measured. The activities of mitochondrial and microsomal AMT in cholestatic rat liver were found to be significantly increased between the first and the seventh day, and the first and the twenty eighth day, respectively after CBD ligation. However, the cytosolic AMT activity did not change. The AMT activity in serum was significantly increased between the first and the twenty eighth day after CBD ligation. The Vmax values of the mitochondrial and microsomal AMT in cholestatic rat liver were significantly increased at the seventh day after CBD ligation. On the other hand, the Km values of the above hepatic enzyme did not vary in all the experimental groups. Therefore, the above results indicate that the biosynthesis of AMT was increased in cholestatic rat liver. The elevated activity of serum AMT is most likely caused by increased hepatocytes membrane permeability due to cholestasis mediated liver cell necrosis.