Hepatic microsomal enzyme activity in patients with non-insulin dependent diabetes mellitus (NIDDM) and its clinical significance

Abstract

ABSTRACT. Hepatic microsomal enzyme activity was investigated in 280 patients with diabetes mellitus. The oral antipyrine test was used as an in vivo index, and cytochrome P-450 content and arylhydrocarbon hydroxylase activity, determined from liver biopsies (80 subjects), were used as in vitro indices of the liver microsomal enzyme system. Indices of both in vivo and in vitro liver metabolism were decreased in patients with noninsulin dependent diabetes (NIDDM, type 2) as compared to subjects with insulin dependent diabetes (IDDM, type 1) and with age- and sex-matched controls. Drug-induced activation of hepatic enzyme system in type 2 patients having reduced microsomal enzyme activity resulted in improved drug metabolizing ability and also improved glucose utilization. In addition, a decrease of hepatic fat content and a change in serum lipid levels were observed. The function of the hepatocellular endoplasmic reticulum, as measured by microsomal enzyme activity, hence seems to be an important factor in the regulation of glucose metabolism in type 2 diabetics. Key words: Diabetes mellitus, microsomal enzyme activity, blood glucose, liver histology.