Open AccessEffect of Sodium Ions on Calcium Movements in Isolated Synaptic Terminals
Author(s) -
M. P. Blaustein,
William P. Wiesmann
Publication year - 1970
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.66.3.664
Subject(s) - calcium , sodium , ouabain , chemistry , biophysics , lithium (medication) , choline , membrane , biochemistry , endocrinology , biology , organic chemistry
Calcium accumulation has been studied in isolated presynaptic nerve terminals from rat brain. Calcium influx is increased when external sodium is replaced by lithium or choline, or when the internal sodium concentration is increased by treatment with ouabain. Calcium efflux is reduced when external sodium is replaced by lithium. The lithium-stimulated calcium accumulation appears to be associated with the nerve terminals, and not with mitochondria or membrane fragments. It is dependent upon an osmotically sensitive surface membrane. The results are consistent with the hypothesis that calcium is actively extruded from mammalian central neurons by a mechanism which exchanges calcium for sodium, and which derives its energy from the sodium concentration gradient.