Simultaneous oscillations of Ca2+ efflux and tension generation in the permealized plasmodial strand of physarum
✍ Scribed by Yoshimoto, Y. ;Matsumura, F. ;Kamiya, N.
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1981
- Weight
- 567 KB
- Volume
- 1
- Category
- Article
- ISSN
- 0271-6585
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✦ Synopsis
Abstract
Calcium is now generally thought to play a key role in regulating a variety of cellular movements. When the plasmodium of Physarum polycephalum was treated with the calcium‐ionophore A23187 or the quasi‐ionophore amphotericin B, Ca^2+^ leaked out. Ca^2+^ efflux into the ambient solution from the plasmodial strand segment was measured by the luminescence of a photoprotein aequorin, and the tensile force production was recorded simultaneously. Ca^2+^ efflux oscillated with the same period as the cycle of tension generation in the strand, but the phase of cyclic changes in Ca^2+^ efflux was opposite to that of tension generation. That is, Ca^2+^ efflux fell in the increasing tension phase and rose in the decreasing tension phase. Cyclic changes in efflux of Ca^2+^ are provisionally interpreted as reflecting corresponding changes in concentrations of free Ca^2+^ in the cytoplasm.