Impact of nitric oxide on renal hemodynamics and glomerular function: modulation by atherogenic lipoproteins?

During the last decade, our understanding of the role of nitric oxide for central renal functions has greatly been enhanced. We know now that nitric oxide is produced in renal arteries, macula densa, glomeruli, and tubules by different NO-synthases. Nitric oxide contributes to physiological regulation of renal blood flow, renal autoregulation, tubuloglomerular feedback, renin release, pressure natriuresis, and tubular function. The physiological role of nitric oxide can be modulated by a variety of pathophysiological influences, such as dyslipidemia, diabetes mellitus, hypertension, specific drugs, or radiocontrast agents. In this article, the possible interactions between nitric oxide and atherogenic lipoproteins with regard to important renal functions and development of glomerulosclerosis have been stressed. Atherogenic lipoproteins impair endothelium-dependent, nitric oxide-mediated dilations of renal arteries. The underlying mechanism involves formation of reactive oxygen species which inactivate nitric oxide. Lipoproteins induce formation of oxygen radicals not only in arteries, but also in glomeruli and juxtaglomerular cells, causing, e.g., stimulation of renin release. Although interactions between lipoprotein and nitric oxide take place at different levels, they finally may contribute to renovascular hypertension. Future studies will have to prove that treating hyperlipidemia has a positive influence on nitric oxide-mediated renal functions.