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Sensitivity of Calcium Efflux from Squid Axons to Changes in Membrane Potential

Overview
Journal J Gen Physiol
Specialty Physiology
Date 1975 Feb 11
PMID 1117279
Citations 46
Authors
L J Mullins
F J BRINLEY Jr
Affiliations
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Abstract

Squid giant axons were internally dialyzed with a medium free of metabolic substrates but containing 45Ca buffered with EGTA to concentrations of free Ca++ in the range 0.01-230 muM. At (Ca)i of 1.0 muM OR GREATER, Ca efflux was in the range of 1-3 pmol/cm2 s, was dependent on (Na)o and (Ca)o, and was sensitive to membrane potential. At lower (Ca)i, the sensitivity of Ca efflux to membrane potential was greater. Hyperpolarization of the membrane increased, and depolarization decreased Ca efflux over the range of potentials studied (-20 to -100 mV). The maximum sensitivity of Ca efflux to membrane potential was of the order of an e-fold increase in Ca efflux for a 25-mV increase in Em; this sensitivity of Ca efflux to membrane potential was lost if (Na)o was removed and was greatly reduced when (Ca)i was increased to 230 muM.

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References
1.
BRINLEY Jr F, Mullins L . Sodium extrusion by internally dialyzed squid axons. J Gen Physiol. 1967; 50(10):2303-31. PMC: 2225661. DOI: 10.1085/jgp.50.10.2303. View
2.
Baker P, HODGKIN A, Ridgway E . Depolarization and calcium entry in squid giant axons. J Physiol. 1971; 218(3):709-55. PMC: 1331609. DOI: 10.1113/jphysiol.1971.sp009641. View
3.
DiPolo R . Effect of ATP on the calcium efflux in dialyzed squid giant axons. J Gen Physiol. 1974; 64(4):503-17. PMC: 2226158. DOI: 10.1085/jgp.64.4.503. View
4.
DiPolo R . Calcium efflux from internally dialyzed squid giant axons. J Gen Physiol. 1973; 62(5):575-89. PMC: 2226134. DOI: 10.1085/jgp.62.5.575. View