Effect of taurine on neurotransmitter release from insect synaptosomes.
The effect of taurine on the release of [3H]acetylcholine ([3H]ACH) and [3H]gamma-aminobutyric acid ([3H]GABA) from preloaded locust synaptosomes has been studied. Veratridine (100 microM) and K+ (100 mM) both evoked [3H]ACh release and this was reduced in a concentration-dependent manner by taurine (5, 10, and 20 mM). In contrast to this, veratridine induced no observable release of [3H]GABA, and the response to K+ was slight. In the presence of taurine, however, a concentration-dependent enhancement of [3H]GABA release was observed. Since nipecotic acid (1 mM), an inhibitor of neuronal GABA uptake, also revealed [3H]GABA release induced by veratridine, it is suggested that both this effect and that of taurine are due to prevention of GABA reuptake. These results suggest that taurine may act as a neuromodulator in insects.
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D002794:Choline / Q000378:metabolism; D006110:Grasshoppers / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009557:Nipecotic Acids / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011392:Proline / Q000031:analogs & derivatives*; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D013654:Taurine / Q000494:pharmacology*; D014701:Veratridine / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D018377:Neurotransmitter Agents; D009557:Nipecotic Acids; D013654:Taurine; C030278:nipecotic acid; D005680:gamma-Aminobutyric Acid; D014701:Veratridine; D011392:Proline; C010983:homoproline; D002794:Choline; D000109:Acetylcholine; D011188:Potassium