Selective ET(A) receptor blockade protects against cisplatin-induced acute renal failure in male rats

The present study aims to investigate the possibility that inhibiting the physiological function of endothelin-1 (ET-1) by blocking its receptors would significantly decrease the nephrotoxic effect of cisplatin. Therefore the study was designed to investigate the effect of treatment with BQ-123, the selective endothelin receptor-A (ET(A)) blocker, and bosentan, the non-selective endothelin receptor blocker, on the cisplatin-induced structural, functional, and biochemical alterations in the rat kidney. Rats were divided into four groups: control (given a single dose of normal saline, i.p.), cisplatin (given a single dose of cisplatin, 6mg/kg, i.p.), cisplatin+BQ-123 (1mg/kg, i.p.), and cisplatin+bosentan (30mg/kg, orally via gavage). Each of the two blockers was administered in two doses; 1h before and one day after the cisplatin dose. Acute cisplatin administration resulted in significant increases in blood urea nitrogen and serum creatinine concentrations at 96h following cisplatin injection. Increased concentrations of malondialdehyde, tumor necrosis factor-α (TNF-α) and caspase-3, decreased nitric oxide (NO) production and superoxide dismutase (SOD) activity in kidney homogenates were observed at 96h following cisplatin injection, in addition to a typical 'acute tubular necrosis' pattern. BQ-123 ameliorated the structural and functional injuries caused by cisplatin mainly via restoring SOD activity, in addition to other antioxidant parameters, NO, TNF-α and caspase-3 concentrations. This study further proves that ET(A) but not ETB receptors are involved in cisplatin-induced nephrotoxicity. The selective ET(A) antagonist BQ-123 ameliorated the cisplatin-induced deleterious effects and showed reno-protective effect against cisplatin-induced acute renal damage.