title: Studies on the mechanism of cell elongation in Blepharisma japonicum. II. Changes of the membrane potential measured by an electrode sensitive to tetraphenyl phosphonium.
abstract: An electrode sensitive to tetraphenyl phosphonium (TPP+) was applied to monitor the changes in the membrane potential of the ciliate Blepharisma japonicum during the process of cell elongation. Uptake of TPP+ by Blepharisma cells was observed when they were incubated in a medium containing 2 x 10(-6)M TPP+. Subsequent light stimulation (3,000 lux) led to an efflux of accumulated TPP+ from the cells, indicating that depolarization of the plasma membrane occurred with the concomitant cell elongation. TPP+ efflux was always observed whenever cell elongation was induced in response to various stimuli: valinomycin (10(-6)M), K+ (30 mM), Co2+ (5 mM), and Ca2+ (5 mM). Furthermore, elongation was also evoked by electrical stimulation. These observations indicate that membrane depolarization is involved in the process of cell elongation in Blepharisma.
authors: Laboratories of Cell Biology, Faculty of Integrated Arts and Sciences, Hiroshima University, Japan.
authors: M
authors: M
authors: Ishida
authors: K
authors: K
authors: Utsumi
authors: T
authors: T
authors: Suzaki
authors: Y
authors: Y
authors: Shigenaka
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D016798:Ciliophora / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure; D003035:Cobalt / Q000494:pharmacology; D004558:Electric Stimulation; D004566:Electrodes; D008027:Light; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D011188:Potassium / Q000494:pharmacology; D014634:Valinomycin / Q000494:pharmacology
chemical_list: D009861:Onium Compounds; D009943:Organophosphorus Compounds; D014634:Valinomycin; D003035:Cobalt; D011188:Potassium; D002118:Calcium; C013289:tetraphenylphosphonium