Abstract
The resting membrane potential in excitable cells of Aldrovanda trap-lobes is composed of diffusion and electrogenic potentials. The diffusion potential, about -100 mV in artificial pond water, was determined from the external K+ and Na+ concentrations. The permeability ratio, PNa/PK of the membrane was estimated to be about 0.3. The electrogenic potential hyperpolarized the membrane to about -140 mV. The peak value of the action potential increased by +26 mV with a tenfold increase in the external Ca2+ concentration. The action potential was blocked by an application of the Ca2+ chelater or the Ca channel blocker, LaCl3. Cells showed additional Ca2+ influx (7.8 pmole/cm2 impulse) during membrane excitation. These facts suggest that the transient increase in Ca2+ influx causes the action potential present in cells of Aldrovanda trap-lobes.
Original language | English |
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Pages (from-to) | 1-13 |
Number of pages | 13 |
Journal | Plant and Cell Physiology |
Volume | 26 |
Issue number | 1 |
Publication status | Published - 1985 Jan 1 |
Keywords
- Action potential
- Aldrovanda vesiculosa
- Electrogenic pump
- Transient Ca2+ influx
ASJC Scopus subject areas
- Physiology
- Plant Science
- Cell Biology