Comparison of converting enzyme inhibitor and calcium channel blocker in SHR with nephrotoxic serum nephritis

In order to compare the protective effects of angiotensin converting enzyme inhibitors (ACEI) and calcium channel blockers (CCB) on the renal function in experimental nephritis, nephrotoxic serum nephritis was induced in male spontaneously hypertensive rats (SHR). The above drugs were then chronically administered to different groups, as follows: the ACEI-treated group (n = 7) received captopril (150 mg/kg/day), and the CCB-treated group (n = 6) was given both nifedipine (40 mg/kg/day) and nisoldipine (20 mg/kg/day). The control group (n = 8) received a placebo. Although the control group developed marked hypertension and proteinuria, the rats treated with either ACEI or CCB demonstrated a significant and equivalent decrease in mean arterial pressure and urinary protein excretion. At 15 weeks after the injection of nephrotoxic serum, all rats were anesthetized with Inactin, and the glomerular filtration rate (GFR) and renal plasma flow (RPF) were measured. In the control group, GFR and RPF were markedly attenuated. However, both were preserved at much higher levels in the ACEI-treated group, and GFR was also maintained to a similar degree in the CCB-treated group. Histological studies were carried out after the clearance studies. As a result, it was found that the ACEI treatment significantly limited the development of glomerulosclerosis, whereas CCB modestly ameliorated the glomerular structural lesions. Moreover, ACEI significantly reduced the serum cholesterol, while CCB did not exert such an effect. These results suggest that both ACEI and CCB have a therapeutic effect in experimental glomerulonephritis models which are accompanied by hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)