The N-type and L-type calcium channel blocker cilnidipine suppresses renal injury in Dahl rats fed a high-salt diet

The aims of the present study were to compare the effects of cilnidipine [L-type/N-type calcium channel blocker (CCB)] and amlodipine (L-type CCB) alone or in combination with the angiotensin II receptor blocker (ARB), valsartan, on blood pressure (BP), kidney function in Dahl salt-sensitive (DS) rats. DS rats fed a high-salt diet were divided into six groups; control (n = 13), two CCB (cilnidipine or amlodipine) groups at 1 mg/kg/day (n = 10), ARB (valsartan) at 10 mg/kg/day (n = 12), cilnidipine + valsartan (CV, n = 12), and amlodipine + valsartan (AV, n = 12). BPs were lower in the combination therapy groups than in those given either drug alone, but only CV inhibited the increase in urinary albumin excretion (UAE) and lowered the glomerular sclerosis score. In addition, AV elevated plasma renin activity and the angiotensin II concentration, and thus failed to inhibit increases in UAE and to lower glomerular sclerosis score. In conclusion, combination therapy with CCB and ARB decreases BP more effectively than either drug alone. When used in combination with valsartan, cilnidipine is more effective than amlodipine for preventing kidney injury.