• 作者： 蔡明正; 彭奕象; 張傳?
• 作者服務機構： 國立臺灣大學醫學院藥理學研究所
• 中文摘要： 本文以電生理學之方法，研究南美洲響尾蛇肌毒素Crotamine（1 μg/ml）在大花鼠伸趾長肌（快肌）及比目魚肌（慢肌），肌細胞膜之作用。 Crotamine可使大花鼠快肌及慢肌之肌細胞膜膜電位產生不可逆之去極化。此項去極化現象，可以河豚毒素對抗之。Crotamine可以抑制直接刺激肌細胞膜所誘發快肌及慢肌動作電位（action potential）之幅度（amplitude）及其上升速率(rate of rise）。它也顯著的減少慢肌肌細胞膜之膜電阻（input resistant），空間常數（space constant）及單位面積膜電阻（transverse membrane resistant）。快肌及慢肌之延緩性電流整流效應（delayed rectification），雖經Crota-mine處理二小時，仍然不受影響。 由以上實驗結果，本文結論Crotamine對快肌及慢肌均有作用。其作用機構不但可能作用在休止之鈉離子管道（res-ting sodium permeability or resting sodium channel），同時也可能作用在動作之鈉離子管道（activating sodiumpermeability or activating sodium channel）。
• 英文摘要： The effect of crotamine (1 μg/ml), a toxin isolated from South American rattle snake venom, on therat extensor digitorum longus (EDL) and soleus muscle membrane was studied by electrophysiologicalmethods. Crotamine irreversibly depolarized the resting membrane potential of EDL and soleus muscle byabout 7%-15% of control. Tetrodotoxin significantly reversed the crotamine induced depolarizationof the membrane. Crotamine decreased the amplitude as well as the rate of rise of the directly elicitedaction potential of the EDL and soleus muscle. It also decreased the input resistance, space constant,and transverse membrane resistance of the soleus muscle. The delayed rectification of both EDL and soleusmuscle was not significantly affected even after 2 hours of incubation with crotamine. It is suggested that crotamine significantly affects the resting and activating sodium permeabilityof the mammalian muscle.
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