Effect of Nitric Oxide Inhibition on Blood Pressure and Renal Sodium Handling: A Dose–Response Study in Healthy Man

Abstract

Nitric oxide (NO) is a ubiquitous vasodilator and an important regulator of renal sodium excretion. To further investigate the role of NO in renal sodium handling, we studied the effects of the NO synthase inhibitor, NG-monomethyl-L-arginine (L-NMMA), in a crossover dose–response study. During NO inhibition mean arterial pressure increased dose-dependently and reached a plateau after 20 minutes of infusion. On the contrary, the fractional excretion of sodium was reduced equally in all three L-NMMA doses. This indicates that sodium excretion is highly sensitive to even small changes in renal NO bioavailability in healthy human.

• nitric oxide
• l-NMMA
• fractional excretion of sodium
• blood pressure
• renin–angiotensin system

ACKNOWLEDGMENTS

We greatly acknowledge the skillful assistance of our laboratory team, including Lisbeth Mikkelsen, Henriette Vorup Simonsen, and Kirsten Nyborg.

Declaration of interest: The project was supported by grants from the Central Denmark Region, Denmark. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.