[Influence of reduced glutathione on changes in the activity of phospholipase C induced by 4-hydroxynonenal]

4-Hydroxynonenal (HNE) is a major end-product of lipid peroxidation. 1 mM HNE inhibits the activity of liver phospholipase C (PL-C) and this effect is prevented by 1 mM GSH; on the contrary GSH is unable to counteract the stimulation of PL-C induced by a low concentration of HNE (100 nM). Other hydroxyalkenals are able to stimulate PL-C at low doses (micromolar or less), the most effective being 4-hydroxyoctenal which acts at picomolar doses. The lack of a correlation between the chain length of the aldehydes used and the degree of PL-C stimulation seems to exclude the possibility that their effect could be due to an aspecific solvent action toward the phosphatidylinositol-4,5-diphosphate used as substrate for the enzymatic assay.