Mechanism of protection of verapamil by preventing neutrophil infiltration in the ischemic rat kidney.

In this study, we tested if the mechanism of protection of a calcium channel blocker, Verapamil (VER), was due to modulation of neutrophil infiltration after ischemia/reperfusion injury, in a rat renal ischemic model. Forty-four Sprague-Dawley rats were subjected to 75 min of warm ischemia and immediate contralateral nephrectomy. The animals were divided into two groups: the ischemic control (IC) group, which received normal saline, and the experimental group that received VER 1.25 mg/kg. The drug was administrated intravenously after ligation of the renal pedicle, before reperfusion. Survival was followed for 7 days. Laboratory tests included renal function tests, with serum creatinine (SCr) and blood urea nitrogen (BUN), light histology and neutrophil infiltration, measured by the myeloperoxidase test in renal tissue. Better survival rate was observed in the VER group (85% at 7 days vs control 50%) (P = 0.08). SCr and BUN at 48 and 72 hr showed a statistical significant difference between the two groups (VER lower than IC P < 0.05). Histological damage was significantly less in the VER group (P < 0.05). Neutrophil infiltration was significantly decreased in the VER group when compared to the IC group (P < 0.05). We concluded then, that VER had a downregulating effect on neutrophil infiltration and this might be an important mechanism of protection during the development of renal ischemic damage.