EFFECTS OF VERAPAMIL ON THE RESPONSE OF THE GUINEA-PIG TRACHEAL MUSCLE TO CARBACHOL
EFFECTS OF VERAPAMIL ON THE RESPONSE OF THE GUINEA-PIG TRACHEAL MUSCLE TO CARBACHOL
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DOI：
10.1111/j.1476-5381.1986.tb10222.x
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发表时间：
1986-06-01
影响因子：
7.3
通讯作者：
TOMITA, T
中科院分区：
文献类型：
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作者：
BABA, K;SATAKE, T;TOMITA, T
1观察维拉帕米对钙(Ca~(2+))或钡(Ba2+)引起的豚鼠气管平滑肌收缩的影响。方法：(1)在过量钾溶液中，(B)在卡巴胆碱存在的情况下，(C)在含有卡巴胆碱的过量钾溶液中，观察维拉帕米对钙(Ca~(2+))或钡(Ba2+)收缩的影响。为了弄清收缩，还研究了二价阳离子的去除和重排的影响。2在含钙组织中，在无钙介质中应用卡巴胆碱可产生一过性收缩，其幅度随无钙溶液作用时间的延长而减小。3在钙离子缺乏、Ba2+含量高的组织中，在Ba2+和无钙介质中应用卡巴胆碱可产生一过性收缩，其幅度随暴露在Ba2+和无钙溶液中的时间延长而减小。4无钙溶液处理40min后，30微米氨基甲酰胆碱(ED50=0.06 mM)比40 mM K+(ED50=0.3 mM)对钙的敏感性更高。在30微米氨基甲胆碱+K+(40 MM)存在下，钙敏感性与单独存在30微米氨基甲胆碱时没有不同。5在无钙溶液中，当K+浓度为40 mM(ED50=1.4 mM)时，组织对Ba2+的敏感性与加入30微米卡巴胆碱时的敏感性(ED50=1.3 mM)无明显差异。6无钙溶液中加入40 mM K+、30微米卡巴胆碱或40 mM K++30微米卡巴胆碱时，维拉帕米使钙离子和Ba2+浓度反应曲线平行右移。7在40 mM K+、30微米卡巴胆碱和40 mM K++30微米卡巴胆碱存在下，维拉帕米对钙离子反应的PA2值分别为7.0、6.5和6.5。在此条件下，维拉帕米对Ba2+反应的PA2值分别为7.1、7.0和7.1。结论：卡巴胆碱产生的持续收缩需要钙离子的内流，Ba2+在此过程中可以替代钙离子。此外，根据钙离子或Ba2+的存在，卡巴胆碱对钙离子通道有不同程度的修饰。这种改变改变了通道对维拉帕米的亲和力。
1 The effects of verapamil on the contraction of the guinea-pig tracheal smooth muscle induced by calcium (Ca2+) or barium (Ba2+) were investigated in three different conditions: (a) in excess K solution, (b) in the presence of carbachol, and (c) in excess K solution containing carbachol. In order to clarify the contractions, the effects of removal and readdition of the divalent cations were also investigated. 2 In Ca2+-loaded tissues, application of carbachol in Ca-free medium produced a transient contraction, the magnitude of which decreased the longer the duration of exposure to Ca2+-free solution. 3 In Ca2+-depleted, Ba2+-loaded tissues, application of carbachol in a Ba2+- and Ca2+-free medium produced a transient contraction the magnitude of which decreased the longer the duration of exposure to the Ba2+- and Ca2+-free solution. 4 After exposure to Ca2+-free solution for 40 min, the sensitivity of the tissue to Ca2+ was greater in the presence of 30 .mu.M carbachol (ED50 = 0.06 mM) than in the presence of 40 mM K+ (ED50 = 0.3 mM). The Ca2+-sensitivity in the presence of 30 .mu.M carbachol plus K+ (40 mM) was not different from that in the presence of 30 .mu.M carbachol alone. 5 In Ca2+-free solution, the sensitivity of the tissue to Ba2+ in the presence of 40 mM K+ (ED50 = 1.4 mM) was not different from that observed in the presence of 30 .mu.M carbachol (ED50 = 1.3 mM). 6 After exposure to Ca2+-free solution, verapamil produced a parallel rightward shift in the concentration-response curves to added Ca2+ and Ba2+ in the presence of either 40 mM K+, 30 .mu.M carbachol or 40 mM K+ plus 30 .mu.M carbachol. 7 The pA2 values of verapamil against Ca2+ responses in the presence of 40 mM K+, 30 .mu.M carbachol and 40 mM K+ plus 30 .mu.M carbachol were 7.0, 6.5 and 6.5, respectively. The pA2 values of verapamil against Ba2+ responses under these conditions were 7.1, 7.0 and 7.1 respectively. 8 It is concluded that the sustained contraction produced by carbachol requires the influx of Ca2+ and that Ba2+ can substitute for Ca2+ in this process. Furthermore, the ionic channels which admit Ca2+ may be modified by carbachol to different degrees depending on the presence of Ca2+ or Ba2+. Such changes alter the affinity of the channel to verapamil.