Hammelsbeck M, Rathmayer W
Faculty of Biology, University of Konstanz, Federal Republic of Germany.
Pflugers Arch. 1989 Mar;413(5):487-92. doi: 10.1007/BF00594178.
(1) Intracellular activities of K+, Na+ and Cl- were measured with ion-sensitive microelectrodes in four different types of muscle fibers in the closer muscle of the crab Eriphia. (2) The membrane resting potentials of the tonic fibers were 9-15 mV more positive than those of phasic muscle fibers. This was due to higher permeability of the membranes of tonic fibers for Na+. (3) The intracellular Na+-activity of tonic fibers was 35-40% higher than that of phasic fibers. Also intracellular Cl- -activity was about 15-33% higher in tonic fibers. (4) No significant differences in K+ -activities were found between physiologically different muscle fiber types. The K+ -equilibrium potentials were always more negative than the resting potentials. In muscle fibers with inhibitory innervation, Cl- -equilibrium potentials were close to (phasic fibers) or slightly more negative (tonic fibers) than resting potentials.
(1) 用离子敏感微电极测量了螃蟹Eriphia闭合肌中四种不同类型肌纤维内的K⁺、Na⁺和Cl⁻活性。(2) 紧张性纤维的膜静息电位比相位性肌纤维的膜静息电位正9 - 15 mV。这是由于紧张性纤维膜对Na⁺的通透性更高。(3) 紧张性纤维的细胞内Na⁺活性比相位性纤维高35 - 40%。紧张性纤维的细胞内Cl⁻活性也高出约15 - 33%。(4) 在生理上不同的肌纤维类型之间未发现K⁺活性有显著差异。K⁺平衡电位总是比静息电位更负。在有抑制性神经支配的肌纤维中，Cl⁻平衡电位接近（相位性纤维）或比静息电位略负（紧张性纤维）。
