Vasopressin-mediated slow EPSPs in a mammalian sympathetic ganglion.
Vasopressin is one of numerous neuropeptides contained in sympathetic ganglia, but whose function remains unresolved. In this report, we present electrophysiological evidence that arginine-vasopressin (AVP) is a neurotransmitter in guinea pig inferior mesenteric ganglion (IMG). AVP superfused over the IMG, in vitro, produced in a population of neurons a membrane depolarization accompanied by a resistance increase, both of which were blocked by a specific V1 receptor antagonist. Moreover, slow excitatory postsynaptic potentials (EPSPs) elicited by repetitive nerve stimulation were attenuated in 75% of cells tested in the presence of excess AVP, and occasionally in the presence of the antagonist. Thus, AVP joins substance P as a putative transmitter of slow potentials in the guinea pig IMG.
Peters
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Kreulen
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D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology / Q000502:physiology*; D002118:Calcium / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects; D004553:Electric Conductivity; D005071:Evoked Potentials; D005728:Ganglia, Sympathetic / Q000187:drug effects / Q000502:physiology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D011945:Receptors, Angiotensin / Q000502:physiology; D017483:Receptors, Vasopressin; D009435:Synaptic Transmission
D011945:Receptors, Angiotensin; D017483:Receptors, Vasopressin; D001127:Arginine Vasopressin; D002118:Calcium