Monoamine Oxidase Activity in Cholestatic Rat Liver

Keimyung Medical Journal 1989;8(1):69-77.

흰쥐 담즙울체간의 Monoamine Oxidase의 활성치

문교철; 곽춘식

Abstract

The effect of cholestasis on hepatic monoamine oxidase (MAO) activity in rat was studied. MAO activities were determined in serum; mitochondria and microsomes of cholestatic liver induced by common bile duct ligation over a period of forty two days. Activity of alanine aminotransferase in serum was also measured. Hepatic mitochondrial and microsomal MAO activities were measured using tyramine; serotonin and benzyla-mine as substrates. And serum MAO activity was measured with benzylamine. Hepatic mitochondrial MAO activities in normal rats were 2;806 p moles ammonia formed/wg protein/min using tyramine as substrate; 1;280 with serotonin and 1;622 with benzylaminine. Hepatic microsomal MAO activities in noraml rats were 1;170 p moles ammonia formed/mg protein/min using tyramine as substrate; 564 with serotonin and 646 with benzylamine. Mitochondrial tyramine oxidase activity in the cholestatic liver decreased significantly between the 3rd and the 42nd day after operation. Benzylamine and serotonine oxidase activities in the cholestatic liver were similar tendencies to that of tyraine oxidase. Microsomal tyramine oxidase activity in the cholestatic liver decreased significantly between the 28th and the 42nd day after operation. Benzylamine oxidase activity in the cholestatic rats was similar tendency to that of tyramine. Serum benzylamine oxidase activity in the cholestatic rat was not detected until the 3rd day after operation but it was 7.3?Axl00m//hr on the 7th day; 18.8 on the 14th day; 15.6 on the 28th day and 13.4 on the 42nd day after operation. The cytosolic alanine aminotransferase activity in the cholestatic liver decreased markedly between the 2nd and the 42nd day after operation but that of serum alanine aminotransferase increased the 2nd day to the 42nd day after operation.