Ureteral occlusion decreases phospholipid and cholesterol of renal tubular membranes

Lipidomic study of kidney in a mouse model with urine flow obstruction

Obstructed urine flow is known to cause structural and functional kidney damage leading to renal fibrosis. However, limited information is available on the change in kidney lipids during urinary tract obstruction. In this study, we investigated the change in lipidome in a mouse model with unilateral ureteral obstruction (UUO). The establishment of the UUO model was confirmed by histopathological examination using transmission electron microscopy. Untargeted liquid chromatography/mass spectrometry was carried out over a time course of 4 and 7 days. Compared to the sham control, the UUO kidney at 7 days showed dilatation of the renal tubule with loss of brush borders and thickening of the capillary endothelium. In the kidney lipidomes obtained from the UUO 7 days group compared to the control, a significant decrease of ceramide, sphingomyelin, phosphatidylcholine, lysophospholipids, and phosphatidylethanolamine was observed, whereas cholesteryl esters, free fatty acids, phosphatidylglycerol, and cardiolipins were significantly increased. The present study revealed the disturbed lipid metabolism in the UUO model, which may provide a clue to potential lipid pathways and therapeutic targets for the early stage of renal fibrosis.

Implications of oxidative stress in the pathophysiology of obstructive uropathy

Although the functional and clinical alterations occurring in patients with obstructive uropathy are not well understood, it has been suggested that oxidative stress could contribute in the mechanism responsible for the impairment of sodium and water balance. This study aimed to test the hypothesis that red wine administration causes an amelioration of both the renal damage and impairment of renal Na(+), K(+)-ATPase activity occurring after ureteral obstruction in the rat. Twenty-four male Wistar adult rats weighting 200-250 g were used. Half of them received a 10-week treatment with wine as the sole fluid source, while the other group received water. Both groups were subjected to 24-h unilateral ureteral obstruction (UUO). Kidney tissue was collected following the relief of the ligature to perform the biochemical assessments. Urine and blood samples were taken at baseline and after the relief. Results show that the treatment with red wine significantly enhances the activity of antioxidant enzymes, and thus reduces renal lipid peroxidation secondary to UUO, which correlated negatively with Na(+), K(+)-ATPase activity. Based on this and other previous data, it could be suggested that red wine administration may prevent renal damage secondary to UUO by inducing enhanced antioxidant potential.