RT Journal Article
SR Electronic
T1 The Kinetics of the Conductance Increase Produced by γ-Aminobutyric Acid at the Membrane of Locust Muscle Fibers
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 580
OP 589
VO 9
IS 4
A1 NEVILLE BROOKES
A1 MARTIN BLANK
A1 ROBERT WERMAN
YR 1973
UL http://molpharm.aspetjournals.org/content/9/4/580.abstract
AB The membrane response to γ-aminobutyric acid (GABA) of locust muscle fibers bathed in "propionate saline" at pH 6.5 is generally biphasic. The slow phase is exponential, and its rate constant (5.5 x 10-3 to 1.0 x 10-2 sec-1) is independent of GABA concentration and relatively insensitive to temperature change (from 26° to 15°). With increasing GABA concentration and temperature, a faster process intervenes. A form of "sensitization" occurs in which the participation of the fast component of the kinetics increases on repeated application of the same GABA concentration. Equilibrium curves of GABA action were obtained at different temperatures, and a van't Hoff plot was constructed. The standard enthalpy change, ΔH°, for the over-all interaction between GABA and receptor is -59.3 kcal/mole.