Evidence that each nerve varicosity on the surface of the mouse vas deferens secretes ATP.
The secretion of ATP from visualised varicosities on the surface of the mouse vas deferens was determined. Small diameter microelectrodes (about 6 microns and 20 microns) were placed over a set of 2 to 5 varicosities visualised with DiOC2(5) in order to record excitatory junctional currents (e.j.c.s') arising from the evoked secretion of quanta. In high external calcium concentrations, [Ca2+]o, the amplitude-frequency distribution of e.j.c.s' was well described by binomial statistics in which binomial parameter n and the number of varicosities were approximately the same. Idazoxan (1 microM) had no effect on the e.j.c.s' or the binomial parameters p and n. Suramin (100 microM) blocked the e.j.c.s' as well as the spontaneous e.j.c.s' (s.e.j.c.s') in all cases, reducing n and p to zero. These results indicate that all varicosities secrete the transmitter blocked by suramin, presumably ATP.
Karunanithi
S
S
Department of Physiology, University of Sydney, NSW, Australia.
Lavidis
N A
NA
Bennett
M R
MR
D000255:Adenosine Triphosphate / Q000378:metabolism*; D058669:Adrenergic alpha-2 Receptor Antagonists; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D004146:Dioxanes / Q000494:pharmacology; D004594:Electrophysiology; D005071:Evoked Potentials / Q000187:drug effects; D019329:Idazoxan; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008839:Microelectrodes; D009411:Nerve Endings / Q000187:drug effects / Q000378:metabolism; D058919:Purinergic P2 Receptor Antagonists; D013498:Suramin / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D014649:Vas Deferens / Q000187:drug effects / Q000294:innervation* / Q000378:metabolism
D058669:Adrenergic alpha-2 Receptor Antagonists; D004146:Dioxanes; D058919:Purinergic P2 Receptor Antagonists; D013498:Suramin; D000255:Adenosine Triphosphate; D002118:Calcium; D019329:Idazoxan