REMODELING OF MOUSE KIDNEY PHOSPHOLIPID CLASSES AND SUBCLASSES BY DIET

Diets containing gammalinolenic acid (18:3n-6) and n-3 polyunsaturated fatty acids (PUFA) can improve renal function and favorably modulate glomerular injury as a result of various inflammatory reactions. In order to elucidate the mechanisms by which dietary n-6 and n-3 PUFA influence renal metabolism, the composition of kidney phospholipid classes and subclasses from mice fed either corn oil (CO) containing 18:2n-6, borage oil (BO) containing 18:2n-6 and 18:3n-6, black currant seed oil (BL) containing 18:2n-6, 18:3n-6 and 18:3n-3, fish-corn oil mix (F/C) containing 18:2n-6, 20:5n-3 and 22:6n-3, and a fish-borage oil mix (F/B) containing 18:2n-6, 20:5n-3 and 22:6n-3 were determined. Three weeks of feeding the different lipids produced no significant change in the relative percentage of any phospholid classes of subclasses of the choline (ChoGpl) and ethanolamine (EtnGpl) glycerophospholipids. In general, FO and F/B diets increased 20:5n-3 and 22:6n-3 in all phospholipids except sphingomyelin (CerPCho). BL feeding produced a smaller relative increase in 20:5n-3 and 22:6n-3. Dietary supplementation with 18:3n-6 (BO, BL and F/B diets) resulted in the accumulation of 20:3n-6 in diacyl-glycerophosphocholine (PtdCho), diacyl-glycerophosphoethanolamine (PtdEtn), phosphatidylinositol (PtdIns), and phosphatidylserine (PtdSer). The combination of 18:3n-6 and n-3 PUFA (F/B diet) elevated the diacyl phospholipid 20:3n-6/20:4n-6 ratio relative to CO, BO, BL, and F/C diets. These findings demonstrate that marked differences exist in the ability of kidney phospholipid classes and subclasses to incorporate dietary PUFA.