Effect of nicorandil on proteinuria in well controlled hypertensive patients

Continuous intravenous infusion of nicorandil for 4 hours before and 24 hours after percutaneous coronary intervention protects against contrast-induced nephropathy in patients with poor renal function

BACKGROUND

We conducted a prospective randomized trial to assess the protective effect of continuous intravenous infusion of nicorandil against contrast-induced nephropathy (CIN) in patients with poor renal function.

METHODS AND RESULTS

We randomly assigned 213 patients who would subsequently undergo elective percutaneous coronary intervention (PCI) and who had a high serum cystatin C level to a saline group (n=107) or a nicorandil group (n=106, nicorandil infused in addition to saline for 4h before and 24h after PCI). There were no significant differences in baseline characteristics between the two groups. However, the average percent increases in serum creatinine and cystatin C following PCI were significantly smaller in the nicorandil group than the saline group. Likewise, the average percent decline in the estimated glomerular filtration rate was smaller in the nicorandil group. Correspondingly, the incidence of CIN was dramatically lower in the nicorandil group than the saline group (2.0% vs. 10.7%, p<0.02). Univariate regression analysis revealed nicorandil treatment to be the only significant predictor of CIN development (odds ratio: 0.173, 95% confidence interval: 0.037-0.812, p=0.026).

CONCLUSIONS

Nicorandil strongly prevents CIN in patients with poor renal function undergoing PCI.

Preventive effect of pretreatment with intravenous nicorandil on contrast-induced nephropathy in patients with renal dysfunction undergoing coronary angiography (PRINCIPLE Study)

PURPOSE

To investigate the effect of pretreatment with intravenous nicorandil on the incidence of contrast-induced nephropathy (CIN) in patients with renal dysfunction undergoing coronary angiography.

MATERIALS AND METHODS

This randomized controlled multicenter study enrolled a total of 166 patients (nicorandil n=81; control n=85) with an estimated glomerular filtration rate <60 mL/min. Nicorandil 12 mg dissolved in 100 mL of 0.9% saline was administered intravenously for 30 minutes just prior to coronary angiography in the nicorandil group. The same volume of only saline was given to the control group. The primary endpoint was the incidence of CIN, defined as >0.5 mg/dL increase or >25% rise in serum creatinine (SCr) concentration within 48 hours of contrast exposure compared to baseline.

RESULTS

The final analysis included 149 patients (nicorandil n=73; control n=76). The baseline characteristics and the total volume of the used contrast (Iodixanol, 125.6±69.1 mL vs. 126.9±74.6 mL, p=0.916) were similar between the two groups. The incidence of CIN also did not differ between the nicorandil and control groups (6.8% vs. 6.6%, p=0.794). There was no difference between the two groups in the relative change in SCr from baseline to peak level within 48 hours after coronary angiography (-1.58±24.07% vs. 0.96±17.49%, p=0.464), although the nicorandil group showed less absolute change in SCr than the control group (-0.01±0.43 mg/mL vs. 0.02±0.31 mg/mL, p=0.005).

CONCLUSION

Prophylactic intravenous infusion of nicorandil did not decrease the incidence of CIN in patients with renal dysfunction undergoing coronary angiography.

Nicorandil, a Katp channel opener, alleviates chronic renal injury by targeting podocytes and macrophages

Nicorandil exhibits a protective effect in the vascular system, which is thought to be due to vasodilatation from opening ATP-dependent potassium channels and donation of nitric oxide. Recently, nicorandil was shown to be renoprotective in models of acute kidney injury and glomerulonephritis. However, the specific mechanisms of renoprotection are unclear. We evaluated the effect of nicorandil on the rat remnant kidney model of chronic kidney disease. Blood pressure was unchanged by a 10-wk course of nicorandil, while albuminuria was significantly reduced. Glomerular injury and tubulointerstitial injury were also ameliorated by nicorandil. Oxidative stress, as noted by renal nitrotyrosine level and urine 8-hydroxy-2′-deoxyguanosine, were elevated in this model and was significantly reduced by nicorandil treatment. Treatment was associated with maintenance of the mitochondrial antioxidant, manganese SOD, in podocytes and with suppression of xanthine oxidase expression in infiltrating macrophages. Interestingly, these two cell types express sulfonylurea receptor 2 (SUR2), a binding site of nicorandil in the ATP-dependent K channel. Consistently, we found that stimulating SUR2 with nicorandil prevented angiotensin II-mediated upregulation of xanthine oxidase in the cultured macrophage, while xanthine oxidase expression was rather induced by blocking SUR2 with glibenclamide. In conclusion, nicorandil reduces albuminuria and ameliorates renal injury by blocking oxidative stress in chronic kidney disease.

Nicorandil as a novel therapy for advanced diabetic nephropathy in the eNOS-deficient mouse

Nicorandil is an orally available drug that can act as a nitric oxide donor, an antioxidant, and an ATP-dependent K channel activator. We hypothesized that it may have a beneficial role in treating diabetic nephropathy. We administered nicorandil to a model of advanced diabetic nephropathy (the streptozotocin-induced diabetes in mice lacking endothelial nitric oxide synthase, eNOSKO); controls included diabetic eNOS KO mice without nicorandil and nondiabetic eNOS KO mice treated with either nicorandil or vehicle. Mice were treated for 8 wk. Histology, blood pressure, and renal function were determined. Additional studies involved examining the effects of nicorandil on cultured human podocytes. Here, we found that nicorandil did not affect blood glucose levels, blood pressure, or systemic endothelial function, but significantly reduced proteinuria and glomerular injury (mesangiolysis and glomerulosclerosis). Nicorandil protected against podocyte loss and podocyte oxidative stress. Studies in cultured podocytes showed that nicorandil likely protects against glucose-mediated oxidant stress via the ATP-dependent K channel as opposed to its NO-stimulating effects. In conclusion, nicorandil may be beneficial in diabetic nephropathy by preserving podocyte function. We recommend clinical trials to determine whether nicorandil may benefit diabetic nephropathy or other conditions associated with podocyte dysfunction.