Background
Revascularization of a stenotic renal artery improves kidney function only in select patients with renovascular hypertension (HT) secondary to atherosclerosis. However, the effects of reversal of renovascular HT (RRHT) on the nonstenotic kidney are unclear. We hypothesized that concurrent hypercholesterolemia (HC) attenuates nonstenotic kidney recovery.
Conclusions
RRHT reverses nonstenotic kidney injury in experimental renovascular HT, but concurrent HC blunts regression of kidney injury, possibly due to predominant vasoconstrictors and oxidative stress. These findings reinforce the contribution of the nonstenotic kidney and of prevailing cardiovascular risk factors to irreversibility of kidney dysfunction after revascularization.
Methods
Female domestic pigs were randomized as Normal, renovascular HT, HT+RRHT, HTC (renovascular HT and HC), and HTC+RHT (n = 7 each). RRHT or sham was performed after 6 weeks of HT. Nonstenotic renal blood flow, glomerular filtration rate, and injurious pathways were studied 4 weeks later.
Results
Mean arterial pressure increased similarly in HT and HTC and decreased after RRHT. Oxidative stress increased in HT and HTC kidneys, and decreased in HT+RRHT, but remained elevated in HTC+RRHT. Renal interstitial fibrosis, glomerulosclerosis, and tubular injury were all attenuated in HT+RRHT, but not HTC+RRHT. Endothelin-1 signaling and PGF2α isoprostane levels were elevated in both HTC and HTC+RRHT pigs. Conclusions: RRHT reverses nonstenotic kidney injury in experimental renovascular HT, but concurrent HC blunts regression of kidney injury, possibly due to predominant vasoconstrictors and oxidative stress. These findings reinforce the contribution of the nonstenotic kidney and of prevailing cardiovascular risk factors to irreversibility of kidney dysfunction after revascularization.