CLA Effects in the Rat Kidney
Experimental health benefits of CLA include amelioration of malignancy and inflammatory disease. We investigated the effects of dietary CLA on the kidney, using the Han:SPRD-cy rat model of renal disease. This model features prominent renal interstitial inflammation and fibrosis that is amenable to dietary modification. Male rats were fed control diets or diets containing 1% CLA. After 8 weeks of feeding, urine creatinine was significantly higher in PKD animals fed CLA (p=0.012). CLA feeding reduced interstitial inflammation (p<0.001), fibrosis (p=0.03) and renal PGE2 release (p=0.02). CLA feeding produced increased renal and hepatic CLA isomer content. As CLA potentially alters eicosanoid synthesis, the protein expression of cytosolic phospholipase A2 (cPLA2), cyclooxygenase-1 (COX-1) and COX-2 were determined. Dietary CLA altered the protein expression of these enzymes. Notably, CLA increased COX-2 protein expression in both normal and diseased kidneys, suggesting that the beneficial effect of CLA on renal injury are via effects on these enzymes, and not the reverse. As inflammation and fibrosis are important components of the progression of chronic renal injury, CLA may be a useful agent in dietary amelioration of renal disease. Supported by the Dairy Farmers of Canada, NSERC and the Children's Hospital Foundation of Manitoba.