ISSN:
1432-1424
Keywords:
giant algal cells
;
membrane potentials
;
microelectrodes
;
lipophilic cations
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Summary The vacuolar equilibrium potential of the lipophilic cation TPMP+ (triphenyl methyl phosphonium) in the giant algaeChara australis andGriffithsia monilis was directly measured. The TPMP+ equilibrium potential was approximately 100mV less negative than the measured vacuolar electrical potential. Thus TPMP+ does not act as a probe of the vacuolar electrical potential and appears to be extruded against an electrochemical gradient. Measurement of the plasmalemma equilibrium potential of TPMP+ showed that extrusion of TPMP+ apparently occurred at both the tonoplast and plasmalemma inChara and at the plasmalemma inGriffithsia. It is concluded that TPMP+ cannot be used as a membrane potential probe inChara orGriffithsia.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01871242
