1994 Volume 17 Issue 1 Pages 35-41
To assess renal benefits of calcium channel blockers (CCBs) and angiotensin converting enzyme inhibitors (ACEIs) in diabetic rats with renal impairment, we administered CCBs, nifedipine (NIF) and benidipine (BEN), or ACEIs, captopril (CAP) and trandolapril (TRA), for 12 weeks, and studied changes in systolic blood pressure (SBP) and urinary protein excretion (UP) in uninephrectomized spontaneously hypertensive rats and Wistar-Kyoto rats with diabetes mellitus induces by streptozotocin administration (WKY-STZ and SHR-STZ). In WKY-STZ, both the CCBs and the ACEIs decreased SBP and UP similarly. UP of SHR-STZ was more than that of WKY-STZ. Both the CCBs and the ACEIs attenuated the development of hypertension in SHR-STZ similarly. However, UP in the ACEIs group was significantly less than that of the control (no treatment), whereas UP in the CCBs group was not significantly less than that of the control. These results indicate that hypertension may accelerate diabetic nephropathy. They also indicate that reduction of systemic blood pressure does not always lessen the renal injury in this model of rats. ACEIs were more potent in reducing proteinuria than CCBs in this diabetic model in rats partly because ACEIs may preferentially reduce the intraglomerular capillary pressure. (Hypertens Res 1994; 17: 35-41)