Coexistence of non-adrenergic non-cholinergic inhibitory and excitatory neurotransmitters in a large neuronal subpopulation in the vaginal segment of the chicken oviduct.
The presence, distribution and smooth muscle motor effects of galanin and pituitary adenylate cyclase activating peptide (PACAP) were studied in the nerves of the vaginal part of the oviduct of egg-laying hens. Galanin and PACAP immunoreactivity were found both in neuronal perikarya and nerve fibres within the wall of the vaginal segment. Both populations showed a similar distribution pattern. Particularly the circular muscle and the intramural vascular net were richly innervated. A few galanin- and PACAP-IR nerve fibres extended up to the mucosal folds. Multiple labelling showed galanin to be colocalised with PACAP as well as with vasoactive intestinal polypeptide (VIP) and nitric oxide synthase (NOS) in a large, partly intrinsic neuronal subpopulation innervating the smooth muscle wall. Pharmacological in vitro experiments showed that isolated vaginal muscle strips had a spontaneous basal activity that was not affected by the neuronal conductance blocker tetrodotoxin (TTX). Galanin induced concentration-dependent contractions that were TTX-insensitive. PACAP, VIP, nitric oxide (NO) and the NO donor nitroglycerin caused concentration-dependent relaxations that were TTX-insensitive. Electrical field stimulation of isolated muscle strips induced frequency-dependent relaxations that were blocked by TTX and reduced by the NOS blocker L-nitroarginine. These data provide evidence that the vaginal part of the oviduct contains a largely intrinsic, neuronal subpopulation, capable of releasing multiple non-adrenergic, non-cholinergic (NANC) motor agents for the control of local muscular activities. In addition, we provided pharmacological evidence that VIP, NO and PACAP exert an inhibitory and galanin an excitatory action on isolated muscle strips of the vaginal part of the chicken oviduct. Our results suggest that these NANC neurotransmitters play an important role in the regulation of neuromuscular activity in this region.
Costagliola
Anna
A
Department of Biological Structures, Functions and Technology, Faculty of Veterinary Medicine-University Federico II, Naples, Italy.
De Man
Joris G
JG
Majewski
Mariusz
M
Lakomy
Mirek
M
Cecio
Aldo
A
Robberecht
Patrick
P
Pelckmans
Paul A
PA
Adriaensen
Dirk
D
Timmermans
Jean-Pierre
JP
D018663:Adrenergic Agents / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004347:Drug Interactions; D004558:Electric Stimulation / Q000379:methods; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D019004:Galanin / Q000378:metabolism*; D006145:Guanethidine / Q000494:pharmacology; D007150:Immunohistochemistry / Q000379:methods; D066298:In Vitro Techniques; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D009412:Nerve Fibers / Q000378:metabolism; D009474:Neurons / Q000145:classification / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I; D019335:Nitroarginine / Q000494:pharmacology; D005996:Nitroglycerin / Q000494:pharmacology; D010057:Oviducts / Q000166:cytology*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D013779:Tetrodotoxin / Q000494:pharmacology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D014621:Vagina / Q000166:cytology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism
D018663:Adrenergic Agents; D004791:Enzyme Inhibitors; D018727:Muscarinic Antagonists; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D020030:Nitric Oxide Donors; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D019335:Nitroarginine; D014660:Vasoactive Intestinal Peptide; D013779:Tetrodotoxin; D001285:Atropine; D019004:Galanin; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D014446:Tyrosine 3-Monooxygenase; D005996:Nitroglycerin; D006145:Guanethidine