Decreased endothelial nitric oxide synthase in gastric mucosa of rats with chronic renal failure

A fresh look into the pathophysiology of ischemia-induced complications in patients with chronic kidney disease undergoing hemodialysis

Recent case reports of acute esophageal necrosis in patients with chronic kidney disease (CKD) undergoing hemodialysis encouraged us to look beyond hypoperfusion/ischemia as a sole explanation for this dramatic complication. At least three intriguing pathways, ie, accumulation of protein-bound toxins, endotoxin translocation, and altered mucosal defense mechanisms, have been proposed to explain the inherent susceptibility of CKD patients to developing ischemia-related and cardiovascular events. Interestingly, all the proposed pathways can be potentially antagonized or attenuated. At present, however, it is not known whether one pathway predominates or if any interaction exists between these pathways. More solid experimental and clinical data are warranted to acquire a better insight into the complex pathogenesis of CKD-associated ischemia.

Effect of chronic renal failure on nitric oxide metabolism

Chronic renal failure (CRF) is associated with hypertension, endothelial dysfunction, and a strong propensity for arteriosclerotic cardiovascular disease. Nitric oxide (NO) is an endogenous modulator with diverse biological functions. Chronic inhibition of NO synthases (NOS) has been shown to cause hypertension and vasculopathy. In light of these considerations, numerous studies have explored the effect of CRF on NO metabolism with the assumption that NO deficiency may be involved in the pathogenesis of cardiovascular and other consequences of uremia. The purpose of this review is to provide a brief overview of the effect of CRF on (1) the bioavailability of NO substrate, L-arginine; (2) the expression of NOS isoforms in the relevant organs; (3) the interaction of NO with reactive oxygen species that are known to be increased in CRF, and (4) the accumulation of uremic inhibitors of NOS.