title: Nitric oxide regulates peptide release from parasympathetic nerves and vascular reactivity to vasoactive intestinal polypeptide in vivo.
abstract: The possible involvement of nitric oxide (NO) in the vasodilator response to parasympathetic nerve stimulation in the pig submandibular gland in vivo was studied using the NO synthase inhibitor, NG-nitro-L-arginine. The atropine-resistant vasodilation elicited by parasympathetic stimulation (10 Hz, 30 s) and the response elicited by i.v. injection of vasoactive intestinal polypeptide (VIP) were markedly reduced by NG-nitro-L-arginine. Furthermore, peptide release from the gland elicited by nerve stimulation was attenuated after NG-nitro-L-arginine administration. Addition of the NO donor, nitroprusside, reversed the NG-nitro-L-arginine evoked attenuation of the response to nerve stimulation and VIP. Also the cholinergic parasympathetic component and the vascular effect of acetylcholine were reduced by NG-nitro-L-arginine. Furthermore, the NG-nitro-L-arginine-induced attenuation of the vascular responses was partially prevented by milrinone, an inhibitor of the cyclic GMP-regulated phosphodiesterase III. The present results suggest that NO may be crucial for parasympathetic vasodilatation by regulating peptide release and second messenger systems for VIP and acetylcholine.
authors.affiliation: Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Modin
authors.forename: E
authors.initials: E
authors.lastname: Weitzberg
authors.forename: J M
authors.initials: JM
authors.lastname: Lundberg
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001285:Atropine / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism; D004558:Electric Stimulation; D005260:Female; D008297:Male; D020105:Milrinone; D009479:Neuropeptides / Q000378:metabolism*; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D019335:Nitroarginine; D009599:Nitroprusside / Q000494:pharmacology; D010275:Parasympathetic Nervous System / Q000378:metabolism*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011728:Pyridones / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects; D013363:Submandibular Gland / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism; D013552:Swine; D014655:Vascular Resistance / Q000187:drug effects; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D009479:Neuropeptides; D010726:Phosphodiesterase Inhibitors; D011728:Pyridones; D009599:Nitroprusside; D019335:Nitroarginine; D009569:Nitric Oxide; D014660:Vasoactive Intestinal Peptide; D001285:Atropine; D001120:Arginine; D006152:Cyclic GMP; D020105:Milrinone