title: Actions of vasoactive intestinal polypeptide in superior cervical ganglion of the cat.
abstract: Effects of vasoactive intestinal polypeptide (VIP) in the superior cervical ganglion (SCG) of the cat were investigated in situ. Vasoactive intestinal polypeptide (0.075-1.5 nmol) induced a dose-dependent depolarization of the superior cervical ganglion, characterized by a long-latency, slow onset, small amplitude and long duration. Initial short-lasting hyperpolarization of the superior cervical ganglion was observed in 5 out of 8 experiments after administration of VIP in a dose of 0.75 nmol. Vasoactive intestinal polypeptide (0.075-1.5 nmol) unmasked the muscarinic slow negative potential, following the compound action potential and unmasked or enhanced the stimulus-bound decremental oscillatory potentials induced by the muscarinic agonist McN-A-343 in the superior cervical ganglion. Vasoactive intestinal peptide induced a slight, but significant increase in the amplitude of the postganglionic action potentials evoked by preganglionic stimulation. The data mentioned above suggest that VIP may act as a neuromodulator of cholinergic transmission at the ganglionic synapse.
mesh_terms: D000818:Animals; D002415:Cats; D004594:Electrophysiology; D005260:Female; D005728:Ganglia, Sympathetic / Q000187:drug effects* / Q000502:physiology; D008297:Male; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
chemical_list: D014660:Vasoactive Intestinal Peptide