Neurotransmitter-role of VIP in non-adrenergic relaxation of feline myometrium.
The feline myometrium is heavily innervated by VIP-containing nerve fibres. Transmural electrical stimulation (10 Hz, 2 msec, 150 mA) of muscle strips from feline myometrium in the presence of adrenoreceptor blocking agents caused a muscle relaxation. The smooth muscle relaxation was accompanied by a significant increase in immunoreactive VIP in the superfusate. Both the VIP release and the relaxation were completely annulled by tetrodotoxin, a selective blocker of axonal conduction. Furthermore, passive immunoneutralization with antiserum against VIP markedly reduced the smooth muscle relaxation induced by electrical stimulation. In the light of the previously demonstrated smooth muscle relaxant effect of VIP, the present findings indicate that the peptides may participate as neurotransmitter in non-adrenergic relaxation of the feline myometrium.
D000818:Animals; D002415:Cats; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D009215:Myometrium / Q000187:drug effects / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000502:physiology*; D013565:Sympatholytics / Q000494:pharmacology; D014660:Vasoactive Intestinal Peptide / Q000502:physiology*
D018377:Neurotransmitter Agents; D013565:Sympatholytics; D014660:Vasoactive Intestinal Peptide