THE EFFECT OF ENDOGENOUS NITRIC-OXIDE ON NEUROGENIC PLASMA EXUDATION IN GUINEA-PIG AIRWAYS

We studied the effect of endogenous nitric oxide (NO) on vagally induced plasma exudation into guinea-pig trachea and main bronchi using I-125-albumin as a plasma marker. N(G)-Nitro-L-arginine methyl ester (L-NAME, 1-10 mg/kg) dose dependently inhibited neurogenic plasma exudation. Intravenous phenylephrine which simulated the vasopressor effect as L-NAME (10 mg/kg) was without effect. The effect of L-NAME (5 mg/kg) was reversed by L-arginine (50 mg/kg). These results suggest that endogenous NO may contribute to neurogenic inflammation in the airways.