Effects of a new calcium antagonist, manidipine, on the renal hemodynamics and the vasoactive humoral factors in patients with diabetes mellitus.

The effects of manidipine (10 mg/day for 7 days) on the renal hemodynamics and vasoactive humoral factors were examined in 6 adults with diabetes mellitus (DM). Mean duration of DM was 9 +/- 2 years; serum creatinine concentration was 0.9 +/- 0.04 mg/dL. Plasma endothelin-1 (ET-1) concentration was 5.4 +/- 0.7 pg/mL before manidipine, compared with 1.9 +/- 0.2 pg/mL in 14 controls (p = 0.03%). Systolic and mean blood pressure decreased significantly during treatment without changes in glomerular filtration rate, renal plasma flow, or filtration fraction. Renal vascular resistance tended to decrease and fractional excretion of sodium significantly increased from 1.35 +/- 0.27% to 2.06 +/- 0.47 (p = 2.96%). ET-1 significantly decreased from 5.4 +/- 0.7 pg/mL to 3.5 +/- 0.6 (p = 2.95%), while plasma angiotensin II, atrial natriuretic factor, urinary excretion rate of ET-1, and albumin excretion rate did not change. Manidipine lowers blood pressure without adversely affecting renal function in diabetic patients. Manidipine, which lowers ET-1, may protect from progressive renal injury in diabetics.