[Modification of drug oxidation in rat liver microsomal fractions by mitochondria].

In order to establish possible interaction between mitochondrial membranes and endoplasmic reticulum, the effects of succinate, fumarate and malate (10(-6)--10(-2) M) on N-demethylation of ethylmorphine in liver homogenate, liver homogenate, enriched by mitochondria and in liver sections of newborn animals were studied. In experiments with liver homogenate and liver mitochondria-enriched homogenate the substrates exerted no effect. Addition of mitochondria decreased the homogenate activity by 50%, when NADPH was used as cosubstrate. Studies on liver sections showed the increase of activity only in case of succinate. The activity of liver sections from newborn rate was 30% of that from adult animals. The enzyme activity was suppressed by the Krebs cycle substrates.