[Effects of antihypertensive therapy on the renal function in spontaneously hypertensive rats (SHR) with renal...

To determine whether pharmacological control of blood pressure could affect the renal function and its deterioration in SHR with renal ablation, we studied effects of oral administration of captopril (50 mg/kg/day) and ramipril (10 mg/kg/day), angiotensin converting enzyme inhibitors (ACEI), nilvadipine (10 mg/kg/day) and benidipine (3-6 mg/kg/day), calcium channel blockers (CCB), and indapamide (10 mg/kg/day), a non-thiazide diuretic, for 2 and 12 weeks on systolic blood pressure (SBP), blood urea nitrogen (BUN) and serum creatinine (Scr), endogenous creatinine clearance (Ccr), and urinary protein excretion (UP) in SHR subjected to 5/6 nephrectomy a week before. Three weeks after the surgery, SBP (mmHg) in the untreated group was 253 +/- 8.9 (n = 11), captopril group 156 +/- 8.9 (n = 7, p less than 0.05), ramipril group 176 +/- 12 (n = 7, p less than 0.05), nilvadipine group 146 +/- 8.8 (n = 7, p less than 0.05), and benidipine group 197 +/- 8.5 (n = 7, p less than 0.05). Monotherapy with indapamide (206 +/- 4.8, n = 7, p less than 0.05) induced only a slight decrease in the SBP. Thirteen weeks after the surgery, SBP in the untreated group was 270 +/- 6.9 (n = 14), in the captopril group 191 +/- 4.8 (n = 7, p less than 0.05), in the ramipril group 160 +/- 9.5 (n = 7, p less than 0.05), in the nilvadipine group 177 +/- 13.2 (n = 7, p less than 0.05), and in the benidipine group 150 +/- 4.9 (n = 7, p less than 0.05). BUN was lower in the captopril and nilvadipine groups but not in the other treatment groups compared with the untreated group. Scr was lower in the ACEI groups. Ccr was higher in the ACEI and benidipine groups. UP was lower in all treatment groups. These results indicate that the similar reduction of SBP by ACEI and CCB has the potential to preserve renal function and to lessen renal damage in this model. Furthermore, they also suggest that ACEI have the potential to ameliorate renal function in this model. However, it remains to be determined why, despite the similar effects on SBP, deterioration of renal function in this model was prevented only by treatment with the ACEI, but not with the CCB.