第6卷‧第4期,
198210
, pp. 479-484
Diazepam在神經一肌作用之研究
- 作者:
蔡明正; 張傳炯
- 作者服務機構:
臺灣大學醫學院藥理學研究所
- 中文摘要:
本文利用大老鼠膈神經-橫膈膜及比目魚肌標本,觀察 Diazepam 在神經一肌之作用。 Diazepam 先加強而後抑制直接及間接刺激所引起之肌收縮力量。大量時,間接刺激所引起之肌收縮較直接刺激所引起者,快被抑制。 Diazepam 並引起持續之肌攣縮。在箭毒素存在下,Diazepam 對直接刺激肌肉所引起之收縮也有先加強而後抑制之現象。 Diazepam 致使運動神經終板自發性終板電位之頻率及幅度增加。但長時間浸浴在高濃度之 Diazepam 溶液時,自發性終板電位之幅度則受到抑制。Diazepam 也抑制運動神經終板,終板電位之幅度。它並且減少神經末梢傳遞物質之量子含量(quantal content)。 Diazepam 延長肌動作電位之半衰期,並且可逆的抑制肌動作電位之幅度,上升速率及肌細胞膜之延緩整流效應。 由以上實驗結果顯示 Diazepam 之作用位置極為廣泛。它不但可以減少神經末梢內傳導物質之量子含量,也可以抑制鈉、鉀離子在興奮性細胞膜上之滲透性。
- 英文摘要:
The effect of diazepam on the neuromuscular (NM) transmission was studied on the isolated ratphrenic nerve diaphragm preparation and soleus muscles. Diazepam caused initial potentiation followed byinhibition of both directly and indirectly elicited muscle twitch tension. At higher concentrations ofdiazepam the response to indirect nerve stimulation was always blocked earlier than that to direct musclestimulation. It also induced a sustained muscle contracture. In the d-tubocurarine pretreated preparationdiazepam also induced an initial potentiation followed by inhibition of directly elicited muscle twitchtension. The frequency and amplitude of the rat diaphragm miniature endplate potential were first increas-ed. However, after prolonged incubation, the amplitude of miniature endplate potential was decreased.Then the endplate potential was depressed and the quantal contents decreased. Diazepam prolonged thehalf decay time of the directly elicited muscle action potential and inhibited the delayed rectification ofthe muscle membrane. However, it inhibited the amplitude and rate of rise of action potential at higherconcentrations (0.14 mM and above). It is concluded that diazepam potentiated the muscle twitch tensionby interference with potassium conductance of the muscle membrane. At higher concentration diazepamalso decreased sodium conductance of the excitable membrane.
- 中文關鍵字:
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- 英文關鍵字:
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