EXTRACTION AND PARTIAL CHARACTERIZATION OF DIALYZABLE PRODUCTS ORIGINATING FROM THE PEROXIDATION OF LIVER MICROSOMAL LIPIDS AND INHIBITING MICROSOMAL GLUCOSE 6-PHOSPHATASE ACTIVITY

The dialysate obtained from a system containing actively peroxidizing liver microsomes shows inhibitory effects on glucose 6-phosphatase activity of freshly prepared liver microsomes (test system). The inhibitory factors were recovered in extracts obtained from the dialysate with ethyl ether or ethyl acetate. The extraction procedure completely removed the inhibitory activity from the dialysate. A partial separation of the products present in the dialysate extract was obtained by thin-layer chromatography. When the lipid materials eluted from individual bands or groups of bands were tested for inhibitory activity, it was found that various Chromatographic bands contained various degrees of inhibitory activity, and that the highest inhibitory activity occurs in a well resolved band that is stained yellow by a N,N'-dimethyl-p-phenylene-diamine reagent. Additional studies indicated that this band contains most of the carbonyl functional groups detectable in the unfractionated dialysate extract, while it contains peroxide functional groups in trace amounts only. The peroxide functional groups present in the unfractionated dialysate extract were found to occur in various Chromatographic bands without a well defined relationship with the toxicological activity. It is concluded that lipoperoxidation products highly active in inhibiting microsomal glucose 6-phosphatase activity are fatty aldehydes or other carbonyl compounds, probably provided with a relatively long carbon chain. © 1979.