Johns A, Paton D M
Can J Physiol Pharmacol. 1975 Jun;53(3):410-5. doi: 10.1139/y75-059.
The effect of caesium on the responses of rabbit vas deferens to transmural stimulation was investigated. The tissue responded to transmural stimulation with a phasic spike contraction followed bya sustained contractile response. The sustained response was inhibited by phentolamine and guanethidine and thus apparently results from noradrenaline release from adrenergic nerves. Addition of 2-5mM Cs+ greatly potentiated this secondary response without altering the sensitivity of the tissue to added (minus)-noradrenaline. This potentiation was not due to Cs+ decreasing the neuronal uptake of noradrenaline, or by Cs+ altering prostaglandin synthesis. Addition of 2mM Cs+ significantly increased the amount of (plus or minus)-[3-H] metaraminol released from tissues in response to transmural stimulation (5 Hz). It is suggested that caesium potentiated responses of rabbit vas deferens to transmural stimulation by increasing the amount of transmitter released per nerve impulse, possibly as a result of prolongation of the action potential.
研究了铯对兔输精管对跨壁刺激反应的影响。该组织对跨壁刺激的反应先是出现一个阶段性的尖峰收缩，随后是持续的收缩反应。酚妥拉明和胍乙啶可抑制这种持续反应，因此其显然是由肾上腺素能神经释放去甲肾上腺素所致。添加2 - 5mM Cs⁺可极大地增强这种继发性反应，而不改变组织对添加的（-）-去甲肾上腺素的敏感性。这种增强作用并非由于Cs⁺降低了去甲肾上腺素的神经元摄取，也不是由于Cs⁺改变了前列腺素的合成。添加2mM Cs⁺可显著增加组织在响应跨壁刺激（5Hz）时释放的（±）-[³H]间羟胺的量。有人提出，铯通过增加每个神经冲动释放的递质数量来增强兔输精管对跨壁刺激的反应，这可能是动作电位延长的结果。
