Insights in Blood Pressure

Pubertal Administration of Angiotensin Receptor Blocker Modifies Renal Vascular Structural Alterations in Dahl Salt-sensitive Rats (Effect of ARB on Kidney of Dahl Salt-sensitive Rat)

Salt-induced renal vascular structural changes and their alterations by pubertal treatment with an angiotensin II receptor blocker, olmesartan, were examined in Dahl salt-sensitive (DS) rats using Dahl salt-resistant (DR) rats as controls (n=24 of each strain). DS and DR rats were treated with olmesartan (10 mg/kg/day) or vehicle for two weeks starting from 3 to 4 weeks of age and thereafter fed 4% salt diet (n=8 of each treatment in each strain). The remainders of both strains were fed 0.3% salt diet throughout the study period. At 10-12 weeks of age, flowpressure (F-P) and pressure-glomerular filtration rate (P-GFR) relationships were determined for maximally vasodilated, perfused kidneys. In the rats receiving 0.3% salt diet, the gradient of P-GFR (glomerular filtration capacity against pressure) was less in DS strain than in DR strain, although blood pressure, the gradient of F-P (minimal renal vascular resistance reflecting the overall luminal dimensions of preand post-glomerular vasculature) and the X intercept of P-GFR (preglomerular: postglomerular vascular resistance ratio) did not differ between both strains. In DS strain, blood pressure were higher, the gradient of F-P was greater and the gradient of P-GFR was less in the rats receiving 4% salt diet plus vehicle compared with the rats receiving 0.3% salt diet, although the X intercept of P-GFR did not differ between the two groups. Contrary, the above parameters were not different between the two groups in DR strain. In DS strain, blood pressure was lower and the gradient of P-GFR was greater in the rats receiving 4% salt diet plus olmesartan compared with the rats receiving 4% salt diet plus vehicle, although the gradient of F-P and X intercept of P-GFR did not differ between the two groups. Conversely, the above parameters were not different between the two groups in DR strain. In conclusion, the pubertal treatment with olmesartan could prevent the saltinduced worsening of reduction in glomerular filtration capacity as well as saltinduced increase in blood pressure in DS strain.

Author(s):

Hexing L,Tomoda F, Koike T, Hidenori Y, Ohara M and Inoue H

Abstract | Full-Text | PDF

Share this