Distinct Renal Injury in Early Atherosclerosis and Renovascular Disease

A. R. Chade
2002 Circulation  
Background-Atherosclerotic renovascular disease may augment deterioration of renal function and ischemic nephropathy compared with other causes of renal artery stenosis (RAS), but the underlying mechanisms remain unclear. This study was designed to test the hypothesis that concurrent early atherosclerosis and hypoperfusion might have greater early deleterious effects on the function and structure of the stenotic kidney. Methods and Results-Regional renal hemodynamics and function at baseline
more » ... tion at baseline and during vasoactive challenge (acetylcholine or sodium nitroprusside) were quantified in vivo in pigs by electron-beam computed tomography after a 12-week normal (nϭ7) or hypercholesterolemic (HC, nϭ7) diet, RAS (nϭ6), or concurrent HC and a similar degree of RAS (HCϩRAS, nϭ7). Flash-frozen renal tissue was studied ex vivo. Basal cortical perfusion and single-kidney glomerular filtration rate (GFR) were decreased similarly in the stenotic RAS and HCϩRAS kidneys, but tubular fluid reabsorption was markedly impaired only in HCϩRAS. Perfusion responses to challenge were similarly blunted in the experimental groups. Stimulated GFR increased in normal, HC, and RAS (38.3Ϯ3.6%, 36.4Ϯ7.6%, and 60.4Ϯ9.3%, respectively, PϽ0.05), but not in HCϩRAS (6.5Ϯ15.1%). These functional abnormalities in HCϩRAS were accompanied by augmented perivascular, tubulointerstitial, and glomerular fibrosclerosis, inflammation, systemic and tissue oxidative stress, and tubular expression of nuclear factor-B and inducible nitric oxide synthase. Conclusions-Early chronic HCϩRAS imposes distinct detrimental effects on renal function and structure in vivo and in vitro, evident primarily in the tubular and glomerular compartments. Increased oxidative stress may be involved in the proinflammatory and progrowth changes observed in the stenotic HCϩRAS kidney, which might potentially facilitate the clinically observed progression to end-stage renal disease. (Circulation. 2002;106:1165-1171.)
doi:10.1161/01.cir.0000027105.02327.48 pmid:12196346 fatcat:smnxifnjuzf4rd7577rsssvby4