Effect of N-octylamine on the reduction of mammalian hepatic microsomal cytochrome B5

Abstract

1. 1. In a preceding paper evidence was presented for the endogenous reduction of NAD(P) + by mammalian hepatic microsomes and the concomitant reduction of cytochrome b 5. The experiments reported here demonstrate that low concentrations of n-octylamine, in the presence of limiting quantities of NAD +, cause an increased level of cytochrome b 5 reduction by mouse hepatic microsomes and also delays its reoxidation. 2. 2. These effects are both NAD + and n-octylamine dependent and appear to be due to an activation of the microsomal enzyme causing endogenous reduction of NAD(P) + and also, in part, to inhibition of the autooxidation of reduced cytochrome b 5. 3. 3. Protection from the inhibitory action of sulfhydryl reagents on NADH-cytochrome b 5 reductase was also observed in the presence of n-octylamine. 4. 4. The results suggest that the enzyme(s) involved in the endogenous reduction of NAD(P) + is not the microsomal alcohol dehydrogenase.