Lundy P M, Frew R
Defence Research Establishment Suffield, Medicine Hat, Canada.
Eur J Pharmacol. 1993 Feb 9;231(2):197-202. doi: 10.1016/0014-2999(93)90449-r.
Hololena curta venom a potent inhibitor of voltage sensitive Ca2+ channels and neurotransmitter release in mammalian brain, and synthetic funnel web spider toxin an inhibitor of P channels, were examined for their activity on autonomic nerves. Hololena curta (0.5 to 5.0 micrograms venom protein/ml) potently inhibited motor responses of the cholinergic guinea pig ileum myenteric plexus and the adrenergic rat anococcygeus muscle. Synthetic funnel web spider toxin was inactive at concentrations up to 100 microM. Hololena curta inhibited K+, and electrically evoked release of tritium from labeled superfused tissues. Furthermore, K(+)-contracted rat aorta was not relaxed by Hololena curta thereby precluding effects of Hololena curta on postjunctional L type smooth muscle Ca2+ channels. The pattern of effects of Hololena curta on peripheral autonomic nerves was similar to the N channel inhibitor omega-conotoxin GVIA. These results suggest that Hololena curta venom constituents block Ca2+ channels in peripheral autonomic nerves. The study failed to establish the presence of functional P type Ca2+ channels on these peripheral autonomic nerves and further suggests that N type channels may be exclusively responsible for supplying the Ca2+ necessary for neurotransmitter release in these nerves.
对Hololena curta毒液（一种哺乳动物脑中电压敏感性Ca2+通道和神经递质释放的强效抑制剂）和合成漏斗网蜘蛛毒素（一种P通道抑制剂）对自主神经的活性进行了检测。Hololena curta（0.5至5.0微克毒液蛋白/毫升）能有效抑制胆碱能豚鼠回肠肌间神经丛和肾上腺素能大鼠尾骨肌的运动反应。合成漏斗网蜘蛛毒素在浓度高达100微摩尔时无活性。Hololena curta抑制了K+以及从标记的灌注组织中电诱发的氚释放。此外，Hololena curta不会使K(+)收缩的大鼠主动脉松弛，从而排除了Hololena curta对节后L型平滑肌Ca2+通道的影响。Hololena curta对周围自主神经的作用模式与N通道抑制剂ω-芋螺毒素GVIA相似。这些结果表明，Hololena curta毒液成分可阻断周围自主神经中的Ca2+通道。该研究未能证实这些周围自主神经上存在功能性P型Ca2+通道，进一步表明N型通道可能是这些神经中神经递质释放所需Ca2+的唯一供应者。
