Localization of neuronal-constitutive nitric oxide synthase and secretory regulation by nitric oxide in the rat submandibular and sublingual glands.
The distribution of neuronal-constitutive nitric oxide synthase (ncNOs)-positive nerve fibres was compared immunohistochemically, and the effect of NOs inhibitor and NO scavenger on the secretory response was compared functionally, in the two glands. Numerous ncNOs-positive fibres were distributed around acini in the submandibular gland but scarcely any around acini in the sublingual gland. Within the submandibular ganglion (parasympathetic), the nerve-cell bodies were strongly positive. Within the superior cervical ganglion (sympathetic), the nerve-cell bodies were negative, although some positive nerve fibres were observed. The secretory responses to the electrical stimulation of the chorda were significantly reduced by the NOs inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME, 10(-9)-10(-3) M) in a dose-dependent manner. The NO scavenger, 2-(4-carboxyphenyl)4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (carboxy-PTIO) also reduced the chorda-evoked secretion (10(-9)-10(-6) M). The submandibular secretions evoked by stimulation of the superior cervical ganglion were not affected by L-NAME or carboxy-PTIO. In the sublingual gland, neither L-NAME nor carboxy-PTIO affected chorda-evoked salivary secretion. The histochemical and functional results both suggest that NO plays an excitatory role in the regulation of parasympathetic nerve-induced salivary secretion in the rat submandibular gland, but not in the sublingual gland.
Takai
N
N
Department of Physiology, Osaka Dental University, Hirakata, Japan. takai@cc.osaka-dent.ac.jp
Uchihashi
K
K
Higuchi
K
K
Yoshida
Y
Y
Yamaguchi
M
M
D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D002814:Chorda Tympani Nerve / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005726:Ganglia, Parasympathetic / Q000187:drug effects / Q000201:enzymology; D007093:Imidazoles / Q000494:pharmacology; D007150:Immunohistochemistry; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage / Q000494:pharmacology; D009412:Nerve Fibers / Q000187:drug effects / Q000201:enzymology*; D009474:Neurons / Q000187:drug effects / Q000201:enzymology*; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D015290:Second Messenger Systems / Q000187:drug effects / Q000502:physiology*; D013361:Sublingual Gland / Q000187:drug effects* / Q000294:innervation / Q000378:metabolism; D013363:Submandibular Gland / Q000187:drug effects* / Q000294:innervation / Q000378:metabolism; D017783:Superior Cervical Ganglion / Q000187:drug effects / Q000201:enzymology
D001565:Benzoates; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D007093:Imidazoles; C079393:1,3-dihydroxy-4,4,5,5-tetramethyl-2-(4-carboxyphenyl)tetrahydroimidazole; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester