Involvement of activated prorenin in the pathogenesis of slowly progressive nephropathy in the non-clipped kidney of two kidney, one-clip hypertension

Abstract

The handle region peptide (HRP), a (pro)renin receptor (P)RR blocker, did not prevent the acute nephropathy occurring 2 weeks after clipping in renovascular hypertensive rats. This study was performed to examine the effects of HRP, its scramble peptide, or a saline vehicle on slowly progressive nephropathy occurring in the kidneys of two-kidney, one-clip Goldblatt hypertensive rats. At 2 weeks after clipping, the renal morphology in the clipped and non-clipped kidneys was similar in the three groups of rats. At 12 weeks after clipping, however, the glomerulosclerosis index (GI) and the tubulointerstitial damage (TD) of the non-clipped kidneys of the HRP-treated rats were significantly lower than those of vehicle-treated rats, although the GI and the TD were similar in the rats treated with scramble peptide and vehicle. The GI and the TD of the clipped kidneys were similar in the three groups of rats at 12 weeks after clipping. In the non-clipped kidneys at 12 weeks after clipping, activated prorenin levels, angiotensin II levels and transforming growth factor (TGF)-β mRNA levels of HRP-treated rats were significantly lower than those of vehicle-treated rats, although they were similar in the non-clipped kidneys from the rats treated with scramble peptide and vehicle. In the clipped kidneys at 12 weeks after clipping, activated prorenin levels, angiotensin II levels and TGF-β mRNA levels were similar in the three groups of rats. These results suggest that the ((P)RR)-dependent activation of prorenin contributes to the pathogenesis of slowly progressive nephropathy in the intact kidney in a rat model of renovascular hypertension.