RT Journal Article
SR Electronic
T1 Divalent Cations as Charge Carriers During Two Functionally Different Membrane Currents in the Ciliate Stylonychia
JF The Journal of Experimental Biology
JO J. Exp. Biol.
FD The Company of Biologists Ltd
SP 73
OP 90
VO 88
IS 1
A1 de PEYER, JACQUES E.
A1 DEITMER, JOACHIM W.
YR 1980
UL http://jeb.biologists.org/content/88/1/73.abstract
AB We have investigated the ability of various divalent cations to carry current through membrane channels in ciliates activated by mechanical stimulation and by membrane depolarization. Both types of channels are identified as Ca2+ channels. Whereas Ba2+ ions and Sr2+ ions can replace Ca2+ ions as charge carriers during either kind of current, Mg2+ ions can carry the current evoked by mechanical stimulation but not the current elicited by membrane depolarization. Mn2+ ions did not carry either of these currents, and they reduced the currents carried by Ca2+ions. Our experiments suggest that the mechano-sensitive and the voltage-senstive channels exhibit different selectivities for divalent cations.