Nitric oxide inhibits enterocyte mitochondrial phospholipase D.

Mitochondrial damage is one of the prominent features of cell death in oxidative stress and related pathological conditions. Alteration in membrane lipid composition may be responsible for the mitochondrial damage. In this study, we have shown that intestinal mitochondria contain an active phospholipase D (PLD) which is activated by oxidants, Ca2+ or polyamines and this results in degradation of phosphatidylethanolamine (PE) and formation of phosphatidic acid (PA). This PLD activity is inhibited by nitric oxide (NO) which prevents the lipid alteration in mitochondria when exposed to these agents. This can be reversed by the NO scavenger, haemoglobin. This suggests that alteration of mitochondrial membrane lipid composition by activation of PLD in certain pathological condition such as oxidative stress may be prevented by the simultaneous presence of nitric oxide.