Ohizumi Y, Nakamura H, Kobayashi J
Eur J Pharmacol. 1986 Jan 21;120(2):245-8. doi: 10.1016/0014-2999(86)90548-0.
Geographutoxin II (GTX II), a new peptide toxin, isolated from Conus geographus venom, caused a dose-dependent inhibition of the contractile response of the guinea-pig vas deferens to transmural stimulation at concentrations of 3 X 10(-8) to 10(-6) M. The dose-response curves for noradrenaline, acetylcholine and KCl was not affected by GTX II (2 X 10(-7) to 10(-6) M). The release of noradrenaline induced by veratridine was strongly inhibited by GTX II. These results suggest that the GTX II-induced inhibition of the vas deferens may be a presynaptic effect causing a decrease of transmitter release.
地理锥毒素II（GTX II）是一种从地纹芋螺毒液中分离出的新型肽毒素，在浓度为3×10⁻⁸至10⁻⁶ M时，它对豚鼠输精管对跨壁刺激的收缩反应产生剂量依赖性抑制。去甲肾上腺素、乙酰胆碱和氯化钾的剂量反应曲线不受GTX II（2×10⁻⁷至10⁻⁶ M）的影响。藜芦碱诱导的去甲肾上腺素释放受到GTX II的强烈抑制。这些结果表明，GTX II对输精管的抑制作用可能是一种突触前效应，导致递质释放减少。
