Nitric oxide in the developing kidney.

Although nitric oxide (NO) has a well-established role in regulating renal function in the adult, recent studies point to perhaps an even more critical role for NO in maintaining basal renal blood flow (RBF) and glomerular filtration rate (GFR) in the developing kidney. The immature kidney has enhanced renal hemodynamic and functional responses to stimulation and inhibition of NO synthesis when compared with the adult, and these increased responses are not mediated by prostaglandins. Increased intrarenal activity of NO in the developing kidney counter-regulates the highly activated renin angiotensin system by modulating the angiotensin II-mediated vasoconstriction of the developing renal vasculature, the angiotensin II effects on GFR, as well as renin release.

Role of nitric oxide in the hypoxemia-induced renal dysfunction of the newborn rabbit.

The current study was performed in 30 anesthetized and mechanically ventilated newborn rabbits to investigate the role of the endothelium-derived relaxing factor nitric oxide (NO) in the renal vasoconstriction observed during hypoxemia. Renal blood flow (RBF) and GFR were determined by the clearance of p-aminohippuric acid and inulin, respectively. In nine newborn rabbits (group 1), acute hypoxemia induced a significant decrease in RBF (-17 +/- 7%) and GFR (-11 +/- 6%).

Nitric oxide modulates glomerular filtration and renal blood flow of the newborn rabbit.

The current study was performed in 17 anesthetized and mechanically ventilated newborn rabbits to investigate the role of nitric oxide (NO) in the regulation of basal renal function of the immature kidney. Renal blood flow and glomerular filtration rate were determined by the clearance of p-aminohippuric acid and inulin, respectively. In 9 newborn rabbits (group 1), L-NAME, a NO synthesis inhibitor, significantly increased the renal vascular resistance by 31 +/- 9% and decreased the renal blood flow by 20 +/- 6%.

Nitric oxide and the immature kidney.

Nitric oxide (NO) is a very potent vasodilator synthesized from L-arginine by endothelial cells. By activating guanylate cyclase, it promotes vasodilatation of adjacent smooth muscle cells. NO is thus involved in the control of vascular tone in various organs.