Increased calcium-independent phospholipase A(2) activity in vitamin E and selenium-deficient rat lung, liver, and spleen cytosol is time-dependent and reversible

Long-Evans hooded rats maintained on vitamin E and selenium-deficient diets for 6 weeks from weaning exhibited a pattern of enhancement of calcium-independent phospholipase A(2) activity in spleen cytosol similar to that previously reported for the lung and liver. The spleen cytosols from vitamin E and selenium deficient rats had approximately 5 fold higher activity than the samples from animals maintained on diets sufficient in these two nutrients (control) or deficient in either nutrient alone. The calcium-dependent PLA(2) activity was about 6 fold higher in spleen cytosol of vitamin E and selenium deficient rats compared with cytosolic samples from animals on the other three diets. Time course studies indicated that in rats the calcium-independent phospholipase A(2) activity in lung, fiver, and spleen increased initially between 4 and 6 weeks of consuming the diets deficient in both vitamin E and selenium, mid increased even further again at 7 weeks. This bi-phasic response to the deficiency occurred I week after indicators of vitamin E and Se status had reached minimum levels. When animals that were maintained oil the deficient diet for 6 weeks consumed the control dirt for I week the phospholipase A(2) activity of lung, liver, mid spleen was not different than the activity of the control animals. The malondialdehyde concentration of lung and spleen measured at 6 and 7 weeks correlated positively with the calcium-independent phospholipase A(2) activity. These results indicate that deficiency of vitamin E and selenium in the rat leads to a bi-phasic increase in calcium-independent PLA(2) activity in rat lung, liver and spleen, and that the initial increase can be reversed by partial repletion of the two antioxidant nutrients.