ETHANOL CAUSES DECREMENTS IN AIRWAY EXCRETION OF ENDOGENOUS NITRIC-OXIDE IN HUMANS

Ethanol has previously been demonstrated to inhibit excretion of endogenous nitric oxide (NO) in exhaled air from experimental animals. The aim of the present study was to elucidate if this effect also occurs in human subjects. Healthy volunteers ingested ethanol (0.25 and 1 g kg(-1), 20% in orange juice). Nitric oxide in exhaled air was determined by chemiluminescence. Single-breath analysis of exhaled air was performed and peak values of NO and end expiratory levels of NO and CO2 were determined. Ethanol induced dose-dependent decrements in exhaled nitric oxide. Thus, peak values for nitric oxide in exhaled air, in the first exhalation after breath-holding for 30 s, decreased to 56 +/- 10 and 37 +/- 12% of control 60 min after ingestion of ethanol at 0.25 and 1 g kg(-1) respectively. Rinsing the oral cavity (including gargling) for 15 min with 20% ethanol in juice did not significantly influence NO in exhaled air. Heart rate, blood pressure and end expiratory levels of CO2 were not significantly affected by ethanol ingestion. In conclusion, ethanol decreases levels of nitric oxide in exhaled air in humans, likely by inhibition of airway formation of nitric oxide. The results might be of importance in understanding effects of ethanol and other hydrocarbons.