Inhibitory effect of metalloporphyrins in conjunction with cholesterol on hepatic phospholipase A(2) activityin vivo in rats.

We investigated the effect of cholesterol and the metalloporphyrins cobalt mesoporphyrin (CoMP) and chromium protoporphyrin (CrPP) on phospholipase A(2) (PLA(2)) activity and the consequent hepatic mitochondrial stability as well as on lipid concentrations. Our studies revealed that on administration of cholesterol, CrPP, CoMP as well as simultaneous adminstration of cholesterol and CrPP, there was an inhibition of PLA(2) activity. These moieties may therefore, be agents for preventing destabilisation of the mitochondrial membrane and the consequent pathological conditions which may arise due to membrane lysis. Our results revealed that cholesterol administration increased phospholipid concentration, albeit by modest amounts. Although the independent administration of metalloporphyrins led only to minor elevations in phospholipid concentration, the simultaneous administration of cholesterol and CrPP generated a steep elevation in the concentration of total phospholipid. Since cholesterol inhibits PLA(2) activity it has the potential of being therapeutic agent for preventing the pathological conditions which may arise due to membrane lysis.