Comparison of BAY e 5009 (nitrendipine) with dihydralazine in Wistar rats with experimentally induced nephritis

Chronic administration of nitrendipine (N) prevented the development of serious renal damage in Wistar rats with experimental glomerulonephritis. This effect is in sharp contrast with the action of dihydralazine (D). In the two treated groups, the blood pressure levels were in the same range and had returned to values of about 140 mm Hg. The heart rate and the increase in body weight were identical. Daily urinary protein excretion was significantly lower in the N-treated rats (p less than 0.001). During the experiment, 4 of the 12 D-treated and 6 of the 12 untreated animals died. In contrast, all of the N-treated rats survived. Their blood urea nitrogen and serum creatinine levels were significantly lower (p less than 0.01). Histologically, all untreated nephritic animals and three of eight D-treated rats revealed severe arteriopathy in the large vessels of the kidney and focal calcification of the glomerular and tubular basement membranes. Neither vascular changes nor basement membrane calcification were found in the kidneys of the N-treated group. These results suggest the direct renal prophylactic effect of N by prevention of the cellular calcium overload and the extracellular deposition of calcium.