Potassium and Chloride Effluxes during Excitation of Characeae Cells

元データ 日本植物生理学会


Action potentials of intact and tonoplast-free Characeae cells were studied in relation to the effluxes of K^+ and Cl^-. K^+ efflux was monitored by atomic absorption spectroscopy or direct measurement of ^<42>K efflux. Cl^- efflux was monitored by the Ag-AgCl electrode method. A large K^+ efflux was always observed during excitations irrespective of whether the cell was intact or tonoplast-free. In tonoplast-free cells, the permeability of the plasma membrane for K^+ at the plateau of the prolonged action potential was almost the same as that in the resting state. In many cases, Cl^- efflux was also observed during excitations of intact cells although some cells showed action potentials without a detectable increase in Cl^- efflux. Almost all tonoplast-free cells generated action potentials with no associated increase in Cl^- efflux. These results indicate that some ion other than Cl^- carries inward current which balances the outward current carried by K^+. Calcium ion is discussed as the most probable candidate.


新免 輝男 Department Of Life Science Faculty Of Science Himeji Institute Of Technology
Shimmen Teruo Department of Life Science, Faculty of Science, Himeji Institute of Technology
Kikuyama M Niigata Univ. Niigata Jpn
Shimmen Teruo Department Of Biology Faculty Of Science University Of Tokyo
Tazawa M Fukui Univ. Technol. Fukui Jpn
Tazawa Masashi Department Of Applied Physics And Chemistry Fukui University Of Technology
Kikuyama Munehiro Faculty of Pharmacology, Niigata College of Pharmacy
Oda Kenji Faculty of Education, Fukushima University
Hayama Tomio Faculty of Medicine, Kumamoto University
Hayama Tomio Faculty Of Medicine Kumamoto University
Kikuyama Munehiro Biological Laboratory The University Of The Air.
Kikuyama Munehiro Faculty Of Pharmacology Niigata College Of Pharmacy
Oda Kenji Faculty Of Education Fukushima University
Shimmen Teruo Department Of Biology Faculty Of Science Osaka University:(present)department Of Botany Faculty Of S
Tazawa Masashi Departlnent Of Biology Faculty Of Science Osaka University
Tazawa Masashi Department Of Applied Physics And Chemistry Fukui Institute Of Technology