Rosuvastatin improves vascular function of arteriovenous fistula in a diabetic rat model.

OBJECTIVE: This study investigates the pathogenesis of arteriovenous (AV) fistula failure in patients with diabetes mellitus (DM) and tests the vascular protective effect of rosuvastatin on the fistulous communication of diabetic rats.
METHODS: DM was induced in rats by a single injection of streptozotocin. One week later, a fistula was created in the descending aorta and the adjacent inferior vena cava (aortocaval [AC] fistula). Rats were then randomly assigned to receive placebo or rosuvastatin (15 mg/kg/d) in chow for 2 weeks. Blood flow in the aortic segments of the fistula was measured. Circulating CD34+/KDR+ endothelial progenitor cells (EPCs) were determined 2 weeks after creation of the AC fistulas using flow cytometry. Vascular function of the AC fistulas was assessed by isometric force testing. The expression of proinflammatory genes and generation of superoxide anions in the fistulas were examined.
RESULTS: The number of EPCs was reduced in diabetic rats, and rosuvastatin significantly increased the number of circulating EPCs. Reduced blood flow and impaired endothelium-dependent relaxation in the AC fistula of animals with diabetes was significantly potentiated after treatment with rosuvastatin. Rosuvastatin also attenuated the expression of inducible nitric oxide synthase and nicotinamide adenine dinucleotide phosphate oxidase and generation of superoxide anions in the fistula tissues isolated from diabetic rats.
CONCLUSIONS: We provide the first evidence demonstrating that rosuvastatin improves blood flow and endothelial function of AC fistulas in rats with DM by attenuating the activity of proinflammatory genes and generation of superoxide anions in the remodeled vasculature. CLINICAL RELEVANCE: Arteriovenous (AV) fistula is the most common vascular access for hemodialysis in patients with end-stage renal disease. Studies have shown that blood flow in the AV fistula is significantly reduced in patients with diabetes and the period for maturation of an AV fistula is longer in these patients. The underlying mechanisms of AV fistula failure in diabetes are still poorly understood and there are limited therapeutic approaches that can increase the lifespan of these fistulas. The present study demonstrates that oral administration rosuvastatin improves blood flow and endothelial function of AC fistulas in rats with diabetes, which results from attenuating the activity of proinflammatory genes in the remodeled vasculature, thereby reducing the generation of tissue superoxide anions. Our results may thus enhance our ability to prevent and manage vascular access failure in patients with diabetes with chronic renal disease.