Authors: S A Menzikov M N Karpova M V Kalinina
Publish Date: 2011/11/17
Volume: 152, Issue: 1, Pages: 38-42
Abstract
We studied the effect of Cl− 10–75 mM and textHCO 3 ions 10–25 mM on the ATPdependent GABAA receptorcoupled Cl− channel Cl−ATPase in rat brain plasma membranes The total enzyme activity was detected in the presence of both anions at a Cl−/ textHCO 3 ratio of 51 Cl− textHCO 3 ATPase Specific inhibitors of Ptype transport ATPases Nethylmaleimide ovanadate and oligomycin suppressed Cl− textHCO 3 ATPase while the Cl− and textHCO 3 ATPase activities were low sensitive to these ligands Bicuculline abolished the activating effect of Cl− and textHCO 3 ions on the enzyme textHCO 3 ions had no effect on the ATPdependent Cl− transport into proteoliposomes with the involvement of reconstituted ATPase In experiment with Cl−preloaded liposomes addition of textHCO 3 ions to the incubation medium caused the reversion of Cl− transport ion efflux from liposomes Our results suggest that textHCO 3 ions play an important role in the modification of properties of the ATPdependent GABAA receptorcoupled Cl− channel and GABAA receptorinduced Cl−/ textHCO 3 exchange These ions are probably involved in GABAA receptorinduced Cl−/ textHCO 3 exchange in neuronal membranes
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