Differences in control of parasympathetic vasodilation between submandibular and sublingual glands in the rat.
We examined blood flow in the submandibular gland (SMGBF) and sublingual gland (SLGBF) during electrical stimulation of the central cut end of the lingual nerve (LN) in the urethane-anesthetized rats using a laser speckle imaging flow meter. LN stimulation elicited intensity- and frequency-dependent SMGBF and SLGBF increases, and the magnitude of the SMGBF increase was higher than that of the SLGBF increase. The increase in both glands was significantly inhibited by intravenous administration of the autonomic cholinergic ganglion blocker hexamethonium. The antimuscarinic agent atropine markedly inhibited the SMGBF increase and partly inhibited the SLGBF increase. The atropine-resistant SLGBF increase was significantly inhibited by infusion of vasoactive intestinal peptide (VIP) receptor antagonist, although administration of VIP receptor antagonist alone had no effect. The recovery time to the basal blood flow level was shorter after LN stimulation than after administration of VIP. However, the recovery time after LN stimulation was significantly delayed by administration of atropine in a dose-dependent manner to the same level as after administration of VIP. Our results indicate that 1) LN stimulation elicits both a parasympathetic SMGBF increase mainly evoked by cholinergic fibers and a parasympathetic SLGBF increase evoked by cholinergic and noncholinergic fibers, and 2) VIP-ergic mechanisms are involved in the noncholinergic SLGBF increase and are activated when muscarinic mechanisms are deactivated.
Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan.
Toshiya
T
Sato
Division of Physiology, Department of Oral Biology, School of Dentistry, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan hisayosh@hoku-iryo-u.ac.jp.
Hisayoshi
H
Ishii
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001158:Arteries / Q000294:innervation*; D001783:Blood Flow Velocity; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005730:Ganglionic Blockers / Q000008:administration & dosage; D006727:Hormone Antagonists / Q000008:administration & dosage; D017078:Laser-Doppler Flowmetry; D008036:Lingual Nerve / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D008297:Male; D018727:Muscarinic Antagonists / Q000008:administration & dosage; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D017208:Rats, Wistar; D012039:Regional Blood Flow; D013361:Sublingual Gland / Q000098:blood supply*; D013363:Submandibular Gland / Q000098:blood supply*; D013997:Time Factors; D014628:Vagotomy; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects
D005730:Ganglionic Blockers; D006727:Hormone Antagonists; D018727:Muscarinic Antagonists; D014660:Vasoactive Intestinal Peptide; D000109:Acetylcholine
hemodynamics; muscarinic receptor; noncholinergic; salivary gland; vasoactive intestinal polypeptide