Stimulus-evoked efflux of GABA from preloaded slices of the rabbit oviduct.
The effect of electrical and chemical stimulation on the efflux of [3H]gamma-aminobutyric acid (GABA) from preloaded slices of the rabbit oviduct was examined. Electrical field stimulation significantly increased the outflow of [3H]GABA. This effect could not be prevented by tetrodotoxin or by the removal of Ca2+ from the medium. High K+ concentrations, veratrine and ethylenediamine also evoked a remarkable elevation in the efflux. The release induced by veratrine was completely abolished in a Ca2+-free medium or in the presence of tetrodotoxin, while the release evoked by high K+ or ethylenediamine was resistant to both conditions. These findings indicate that GABA can be released from the oviduct under the effect of depolarizing stimuli, raising the possibility of a physiological interaction between oviductual GABA and its receptors. The characteristics of oviductal GABA efflux differ from those of neuronal and glial GABA release.
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D005187:Fallopian Tubes / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000502:physiology; D011817:Rabbits; D013268:Stimulation, Chemical; D013779:Tetrodotoxin / Q000494:pharmacology; D014702:Veratrine / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D013779:Tetrodotoxin; D005680:gamma-Aminobutyric Acid; D010042:Ouabain; D014702:Veratrine; D011188:Potassium; D002118:Calcium