Effects of sevoflurane and isoflurane on blockade of adult type nicotinic acetylcholine receptors of skeletal muscle of rats by rocuronium

Abstract

Objective To investigate the effects of sevotlurane and isoflurane on blockade of adult nicotinic acetylcholine receptor (e-nAChR) of skeletal muscle of rats by rocuronium.Methods HEK293 cell line was provided by Molecular Biology Laboratory,Chonqing Medical University and cultured in DMEM liquid culture medium containing 10％ bovine calf serum at 37 ℃in incubator filled with 5％ CO2.e-nAChR was expressed heterologously in HEK293 cell using liposome transfection technology.The whole cell patch clamp technology was used to establish the concentration-effect curves for inhibition of acetylcholine (ACh)-induced current.The 5％ inhibitory concentration values ( IC5 ),25 ％ inhibitory concentration values ( IC25 ) and 50％ inhibitory concentration values (IC50) for sevoflurane,isoflurane and rocuronium were calculated.Firstly the inhibitory effect of rocuronium at a concentration of IC25 was studied in the presence of sevoflurane and isoflurane at concentrations of IC5,IC25 and IC50.Subsequently the inhibitory effect of rocuronium at concentrations of IC5,IC25 and IC50 was studied in the presence of sevoflurane and isoflurane at a concentration of IC25.Inhibition of ACh-induced current amplitude was recorded.Results At the concentrations of IC5,IC25 and IC50 sevoflurane or isoflurane had synergistical inhibitory effect on the current amplitude of e-nAChR with rocuronium at the concentrations of IC5 and IC25,while had addition inhibitory effect on the current amplitude of e-nAChR with rocuronium at the concentration of IC50.The inhibitory effect of sevoflurane at the concentration of IC5 on the current amplitude of e-nAChR with rocuronium at the concentration of IC25 was weaker than that of isoflurane,while the inhibitory effect of sevoflurane at the concentration of IC50 on the current amplitude of e-nAChR with rocuronium at the concentration of IC25 was stronger than that of isoflurane.The inhibitory effect of sevoflurane at the concentration of IC25 on the current amplitude of e-nAChR with rocuronium at the concentration of IC5 was weaker than that of isoflurane.Conclusion Either sevoflurane or isoflurane has synergistical blocking effect on e-nAChR with low concentration of rocuronium,while has addition blocking effect with high concentration of rocuronium.Potentiation of blocking effect of rocuronium on e-nAChR by low concentration of sevoflurane is weaker than that by isoflurane,while the potentiation by sevoflurane at high concentration is stronger than that by isoflurane. Key words: Isoflurane; Androstanols; Receptors, nicotinic; Muscle, skeletal; Sevoflurane