Effect of Endogenous Nitric Oxide on Neurogenic Plasma Extravasation in Nasal Mucosa of Rat / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Nitric oxide is a labile neurotransmitter causing vasodilation by relaxing vascular smooth muscle. Endogenous nitric oxide is an important modulator of airway function, but its role in the regulation of airway microvascular leak remains unclear. The purpose of this study was to investigate modulatory action of nitric oxide on capsaicin-induced neurogenic plasma extravasation. MATERIALS AND METHODS: Neurogenic inflammation in rat nasal mucosa was induced by intranasal application of the capsaicin, 50 mM, 50 microliter. Rats were administered i.v. Nw-nitro-L-arginine (L-NNA, 1 to 10 mg/kg), as well as concurrent pretreatment with L-arginine (50 mg/kg). The amount of plasma extravasation was measured by measuring amount of extravasated Evans blue using spectrophotometer and by counting percent area density of Monastral blue-labeled blood vessels. RESULTS: In L-NNA(50 mg/kg) pretreated group, the amount of extravasated Evans blue and percent area density of Monastral blue-labeled blood vessels decreased in a dose-dependent manner (p < 0.01). This inhibition was reversed significantly by adding L-arginine. CONCLUSION: It is suggested that endogenous nitric oxide may have as modulatory role in neurogenic plasma extravasation.