Role of endogenous nitric oxide in the control salivary secretion and blood flow.
- Author:
Wonjae KIM
1
;
Sang Chae NAM
;
Miwon KIM
Author Information
1. Department of Oral Physiology, Chonnam National University, Dental School, Kwangju 501-190, South Korea.
- Publication Type:In Vitro ; Original Article
- Keywords:
Endogenous nitric oxide;
Salivary gland;
L-NAME;
Blood flow;
Salivation
- MeSH:
Acetylcholine;
Animals;
Arginine;
Arteries;
Atropine;
Bradykinin;
Carbachol;
Cats;
Infusions, Intra-Arterial;
Methylene Blue;
NG-Nitroarginine Methyl Ester;
Nitric Oxide*;
Phenylephrine;
Salivary Glands;
Salivation;
Submandibular Gland;
Vasoactive Intestinal Peptide;
Vasodilation;
Vasodilator Agents
- From:The Korean Journal of Physiology and Pharmacology
1997;1(6):809-816
- CountryRepublic of Korea
- Language:English
-
Abstract:
The present study was designed to investigate whether endogenous nitric oxide (EDNO) is involved in submandibular vasodilation and salivation induced by parasympathetic nerve stimulation. Effects of Nw-nitro-L-arginine-methyl ester (L-NAME) which blocks the synthesis of EDNO from L-arginine on the submandibular vasodilation and salivation induced by chorda stimulation or administration of various vasodilators were examined in anesthetized cats. Effect of L-NAME on K+ efflux induced by carbachol was also examined using the excised submandibular slice in vitro. In the submandibular slices, acetylcholine (10(-5) mol/L) or vasoactive intestinal polypeptide (VIP, 10(-5) mol/L) increased NO2 contents, which was prevented by pretreatment with L-NAME. Salivary secretion in response to the chorda stimulation (3 V, 1 msec, 10 ~ 20 Hz) was completely blocked by treatment with atropine (1 mg/kg). Increased blood flow response to the low frequency (1, 2, 5 Hz) stimulation was significantly reduced, whereas the blood flow induced by the higher frequency (10, 20 Hz) stimulation was not affected. Lingual-arterial infusion of L-NAME (100 mg/kg) significantly diminished the vasodilatory and salivary responses to the chorda stimulation at all stimuli frequencies used. Intra-arterial infusion of L-NAME (100 mg/kg) markedly diminished the vasodilatory responses to acetylcholine (5 mug/kg), VIP (5 mug/kg) or bradykinin (5 mug/kg). In the excised submandibular slice, K+ efflux in response to carbachol (10(-5) mol/L) was significantly decrease by pretreatment with L-NAME (10(-5) mol/L). In the isolated submandibular artery precontracted with phenylephrine (10(-5) mol/L), the vasorelaxation induced by ACh (10-7 mol/L) was reversed into a contraction by methylene blue (10(-4) mol/L). These results suggest that EDNO may play an important role in vasodilation and secretion of the submandibular gland.
