Hemin pretreatment ameliorates aspects of the nephropathy induced by mercuric chloride in the rat

Mercuric chloride (HgCl2) is known to be a nephrotoxicant. When HgCl2 is administered into rats, acute renal failure (ARF) is induced. Heme oxygenase-l (HO-1) is antioxidative enzyme and is known to play a protective role against the oxidative injury. To elucidate the cytoprotective role of HO-1 against the nephrotoxicant-induced ARF, we examined the effect of hemin, HO-1 inducer, on HgCl2-induced ARF. Subcutaneous administration of hemin (30 mg/kg body weight) into rats once a day for two successive days obviously induced HO-1 protein in the kidneys at 24 h after the last injection. Under this situation, when HgCl2 (1 mg/kg body weight) was intraperitoneally injected into rats at 24 h after the last injection of hemin improved the serum creatinine (SCr) and blood urea nitrogen (BUN) levels, markers for renal injury, at 24 h after the HgCl2 injection as compared with the control rats without hemin pretreatment (HgCl2 treatment alone). This result was further confirmed by histopathological analysis. These findings strongly suggest that the preinduction of HO-1 ameliorates the subsequent HgCl2-induced acute renal injury. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.