Electrical and mechanical effects of molecular variants of CCK on antral smooth muscle.
Electrical and mechanical effects of molecular variants of CCK on antral smooth muscle.
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CCK 分子变异对窦平滑肌的电和机械效应。
DOI：
10.1152/ajpendo.1978.235.3.e324
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
J. Szurszewski
中科院分区：
文献类型：
--
作者：
K. Morgan;P. Schmalz;V. Go;J. Szurszewski
采用细胞内微电极和标准器官池技术，在体外研究了胆囊收缩素肽的三种分子形式对犬心房环形肌电和机械活动的影响。研究了三种形式：胆囊收缩素的羧基末端八肽（CCK-OP），含有33个氨基酸残基的分子（CCK33），以及含有39个氨基酸的肽“胆囊收缩素变体”（CCK39）。这三种形式都增加了自发宫缩的力量和频率。它们还增加了胃动作电位平台期的频率、幅度和持续时间。阿托品没有阻断任何这些作用，这表明这些肽的作用主要是由于对平滑肌的直接作用。测定了这些肽对肌条收缩力和收缩频率的影响以及对单细胞的平台振幅和动作电位频率的影响的完整剂量-反应曲线。CCK39和CCK-OP的效力相似，两种形式的效力均高于CCK33。
Intracellular microelectrode and standard organ bath techniques were used to study in vitro the effects of three molecular forms of the peptide cholecystokinin on the electrical and mechanical activities of canine antral circular muscle. Three forms were studied: the carboxyl-terminal octapeptide of cholecystokinin (CCK-OP), the molecule containing 33 amino acid residues (CCK33), and the peptide termed "cholecystokinin variant" that contains 39 amino acids (CCK39). All three forms increased the force and frequency of spontaneous contractions. They also increased the frequency and the amplitude and duration of the plateau of the gastric action potential. Atropine did not block any of these effects, suggesting that the action of these peptides was largely due to a direct action on the smooth muscle. Complete dose-response curves were determined for the effect of these peptides on the force and frequency of contraction for muscle strips and for the effect on amplitude of the plateau and frequency of the action potential for single cells. CCK39 and CCK-OP had similar potencies and both forms were more potent than CCK33.