Boev K
Acta Physiol Pharmacol Bulg. 1978;4(3):12-20.
The double sucrose gap is used to study the role of Ca-ions in the electromechanical coupling in the phasic and tonic contractions in the different parts of cat stomach. Extracellular Ca2+ is of primary importance in the activation of the tonic contractions. The regulation of the muscle tone under the action of external stimuli is achieved through gradual changes in the Ca-permeability of the cell membrane. Of primary significance for the activation of the phasic contractions is Ca which is released from the intracellular stores. The Ca2+-influx during the action potential results in additional modelation of the intensity of phasic contractions as well as to a re-charging of the intracellular Ca-depots. It is assumed that the differences in the mechanisms of activation of phasic and tonic contractions result not only from the specificities of membrane control but also from definite differences in the organization of the intracellular systems responsible for these contractions.
双蔗糖间隙用于研究钙离子在猫胃不同部位的相性和紧张性收缩的机电偶联中的作用。细胞外钙离子在紧张性收缩的激活中起主要作用。在外部刺激作用下，肌肉张力的调节是通过细胞膜钙通透性的逐渐变化来实现的。对于相性收缩的激活，从细胞内储存库释放的钙离子起主要作用。动作电位期间的钙离子内流导致相性收缩强度的额外调节以及细胞内钙库的再充盈。据推测，相性和紧张性收缩激活机制的差异不仅源于膜控制的特异性，还源于负责这些收缩的细胞内系统组织的明确差异。
