毒蕈碱对豚鼠离体回肠纵行肌的作用机制
Mechanism of action of muscarine on the longitudinal muscle of the guinea-pig isolated ileum.
作者信息
Ochillo R F, Tsai C S, Tsai M H
出版信息
Br J Pharmacol. 1981 Feb;72(2):225-32. doi: 10.1111/j.1476-5381.1981.tb09117.x.
1 DL-Muscarine elicited a contraction of the ileal longitudinal muscle of the guinea-pig and the contraction was characterized by an after-response. 2 Physostigmine (20 x 10(8) M) potentiated the contraction of the longitudinal muscle elicited by DL-muscarine. 3 Hemicholinium-3 (HC-3) caused a rightward shift of the dose-response curve to DL-muscarine on the ileal longitudinal muscle of the guinea-pig ileum. 4 beta-Bungarotoxin (10 microgram/ml) significantly (P < 0.025) reduced the contraction elicited by DL-muscarine (2.5 X 10(-8) M) suggesting presynaptic release of acetylcholine as an indirect mechanism of action of DL-muscarine. 5 Morphine (1.0 x 10(-8) M) significantly (P < 0.05) reduced the contractions elicited by DL-muscarine (2.5 x 10(-8) M) further suggesting presynaptic release of acetylcholine as an indirect mechanism of action of DL-muscarine. 6 A subthreshold dose of DL-muscarine (2.0 x 10(-10) M) potentiated the effect of acetylcholine (2.5 x 10(-8) M) and the potentiation was blocked by beta-bungarotoxin.
- DL-毒蕈碱可引起豚鼠回肠纵肌收缩，且该收缩具有后效应。2. 毒扁豆碱（20×10⁻⁸ M）增强了DL-毒蕈碱引起的纵肌收缩。3. 半胱氨酸-3（HC-3）使豚鼠回肠纵肌对DL-毒蕈碱的剂量反应曲线右移。4. β-银环蛇毒素（10微克/毫升）显著（P<0.025）降低了DL-毒蕈碱（2.5×10⁻⁸ M）引起的收缩，提示乙酰胆碱的突触前释放是DL-毒蕈碱的一种间接作用机制。5. 吗啡（1.0×10⁻⁸ M）显著（P<0.05）降低了DL-毒蕈碱（2.5×10⁻⁸ M）引起的收缩，进一步提示乙酰胆碱的突触前释放是DL-毒蕈碱的一种间接作用机制。6. 阈下剂量的DL-毒蕈碱（2.0×10⁻¹⁰ M）增强了乙酰胆碱（2.5×10⁻⁸ M）的作用，且该增强作用被β-银环蛇毒素阻断。
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