Enhancement effect of propofol on binding function of GABA_A receptor

Objective:To investigate the influence of propofol on the binding function of GABA A receptor. Methods: By using radioligand receptor binding assay, effects of propofol on the specific binding of 3H GABA and saturation curves of GABA A receptor were observed in cortical membrane preparations from mouse cerebral cortex. Results: Specific binding experiments showed that propofol at the concentrations of 10 300 μmol/L markedly enhanced the specific binding of 3H GABA( P 0.05); whereas no significant increase was seen when propofol lower than 10 μmol/L. GABA A receptor saturated binding experiments showed that dissociation constant K d2 in propofol group(10 μmol/L) was markedly lower than that in control group( P 0.01), but no significant changes of K d2 , B max1 and B max2 were observed between 2 groups( P 0.05). Conclusion: Clinical concentrations of propofol can enhance the binding function of GABA A receptor through increasing the affinity of the low affinity binding site of GABA.