Does NG-monomethyl-L-arginine (L-NMMA) affect mean arterial pressure and fractional excretion of sodium in healthy humans?
Nitric oxide inhibition with L-NMMA increases blood pressure dose-dependently and reduces renal sodium excretion in healthy humans, demonstrating that sodium excretion is highly sensitive to small changes in NO bioavailability.
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.
Larsen et al. (Fri,) studied this question.