Summary
Using an optical method for monitoring membrane potential, spontaneous action potentials in the 7-to 9-somite embryonic precontractile chick hearts were measured. The optical action potential in the 7-to 9-somite embryonic heart was lacking ‘phase 0’ and ‘phase 1’ attributable to the fast Na+ current. The embryonic precontractile heart continued to generate spontaneous action potentials in a Na+-free solution or in the presence of tetrodotoxin. Such an action potential was blocked by adding Co2+, Mn2+, Ni2+, La3+, D-600 or GEDTA, and the frequency, the amplitude, and the rate of rise of the spontaneous action potentials depended closely upon the external Ca2+ concentration; reducing the external Ca2+ concentration resulted in suppression of the spontaneous excitability. From the above results, we concluded that the spontaneous action potential in the early phases of cardiogenesis is characterized as a Ca2+-dependent action potential.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Baccaglini, P.I., Spitzer, N.C. 1977. Developmental changes in the inward current of the action potential of Rohon-Beard neurones.J. Physiol. (London) 271:92–117
Cohen, L.B., Salzberg, B.M. 1978. Optical measurement of membrane potential.Rev. Physiol. Biochem. Pharmacol. 78:35–88
DeHaan, R.L. 1980a. Mechanisms of excitability in developing systems.Curr. Top. Dev. Biol. 16:117–164
DeHaan, R.L. 1980a. Development of rhythmic activity in cardiac cells.In: Physiology of Artrial Pacemakers and Conductive tissues. R.C. Little, editor. pp 21–53. Futura Publiishing Company, Inc., Mount Kisco, New York
DeHaan, R.L., McDonald, T.F., Sacks, H.G. 1976. Development of tetrodotoxin sensitivity of embryonic chick heart cells in vitro.In: Developmental and Physiological Correlation of Cardiac Muscle. M. Lieberman and T. Sano, editors. pp. 155–168. Raven Press, New York
Fujii, S., Hirota, A., Kamino, K. 1980. Optical signals from early embryonic chick heart stained with potential-sensitive dyes: Evidence for electrical activity.J. Physiol. (London) 304:503–518
Fujii, S., Hirota, A., Kamino, K. 1981a. Optical recording of development of electrical activity in embryonic chick heart during early phases of cardiogenesis.J. Physiol. (London) 311:147–160
Fujii, S., Hirota, A., Kamino, K. 1981b. Optical indications of pacemaker potential and rhythm0generation in early embryonic chick heart.J. Physiol (London) 312:253–263
Fujii, S., Hirota, A., Kamino, K. 1981c. Action potential synchrony in embryonic precontractile chick heart: Optical monitoring with potentiometric dyes.J. Physiol. (London) 319:529–541
Hagiwara, S. 1973. Ca spikes.Adv. Biophys. 4:71–102
Hagiwara, S., Byerly, L. 1981. Calcium channel.Annu. Rev. Neurosci. 4:69–125
Hirota, A., Fujii, S., Kamino, K. 1979. Optical monitoring of spontaneous electrical activity of 8-somite embryonic heart.Jpn. J. Physiol. 29:635–639
Hirota, A., Sakai, T., Fujii, S., Kamino, K. 1981. Optical monitoring of spatial spread of initial contraction coupled with action potential in early embryonic heart.Biomed. Res. 2:718–721
Hodgkin, A.L., Huxley, A.F. 1952. A quantitative description of membrane current and its application to conduction and excitation in nerve.J. Physiol. (London) 117:500–544
Hoffman, B.F., Cranefield, P.F. 1976. Electrophysiology of the Heart. McGraw Hill, New York
Ishima, Y. 1968. The effect of tetrodotoxin and sodium substitution on the action potential in the course of development of the embryonic chicken heart.Proc. Jpn. Acad. 44:170–175
Kamino, K., Hirota, A., Fujii, S. 1981. Localization of pacemaking activity in early embryonic heart monitored using voltage-sensitive dye.Nature (London) 290:595–597
Kano, M. 1975. Development of excitability in embryonic chick skeletal muscle cells.J. Cell. Physiol. 86:503–510
Kano, M., Shimada, Y. 1973. Tetrodotoxin-resistance electrical activity in chick skeletal muscle cells differentiated in vitro.J. Cell. Physiol. 91:85–90
Kidokoro, A. 1973. Development of action potentials in a clonal rat skeletal muscle cell line.Nature, New Biol. 241:158–159
Kidokoro, Y. 1975. Sodium and calcium components of the action potential in a developing skeletal muscle cell line.J. Physiol. (London) 244:145–159
Matsuda, Y., Yoshida, S., Yonezawa, T. 1978. Tetrodotoxin sensitivity and Ca component of action potentials of mouse dorsal root ganglion cells cultured in vitro.Brain Res. 154:69–82
Pappano, A.J. 1972. Action potentials in chick atria: Increased susceptibility to blockade by tetrodotoxin during embryonic development.Circ. Res. 31:379–388
Sakai, T., Fujii, S., Hirota, A., Kamino, K. 1981. Ionic mechanism(s) of spontaneous action potential in early embryonic heart.Abstr. 19th Annu. Meet. Biophys. Soc. Jpn. p. 138
Shigenobu, K. 1975. Taiseiki-shinzo no maku-tokusei no henka: Yoion-channel to neurotropic influence.Igaku No Ayumi 91:141–148
Shigenobu, K., Sperelakis, N. 1971. Development of sensitivity to tetrodotoxin of chick embryonic hearts with age.J. Mol. Cell. Cardiol. 3:271–286
Spitzer, N.C. 1979. Ion channels in development.Annu. Rev. Neurosci. 2:363–397
Spitzer, N.C. 1981. Development of membrane properties in vertebrates.Trends Neurosci. 4:169–171
Yanagihara, K., Irisawa, H. 1980. Potassium current during the pacemaker depolarization in rabbit sinoatrial node cell.Pflueger Arch. 388:255–260
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sakai, T., Fujii, S., Hirota, A. et al. Optical evidence for calcium-action potentials in early embryonic precontractile chick heart using a potential-sensitive dye. J. Membrain Biol. 72, 205–212 (1983). https://doi.org/10.1007/BF01870587
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01870587