Abstract: Objective To investigate the effect of oxidative stress induced by glucose oxidase (GO) on the current of α4β2 nicotinic acetylcholine receptor (nAChR). Methods HEK293T cells were co-transfected with plasmid α4 and β2 after 48 h. Experimental groups were divided into control group, GO group and CAT group. To measure the level of reactive oxygen species (ROS), we used confocal microscopy to detect fluorescence intensity by DCFH-DA fluorescent probe; the currents of α4β2 nAChR were detected by whole-cell patch clamp. 1 μmol/L, 10 μmol/L and 30 μmol/L ACh were used to detect the receptor function. 10 μmol/L ACh was used to detect current changes. Results The currents from α4β2 nAChR in HEK293T cells were increased in a dose-dependent manner; the treatment of 3.5 kU/L GO for 1 h significantly incresed the level of ROS in HEK293T cells (P <0.001); with the consecutive application of ACh, the currents in control group were still stable after 10 times administration, while the GO-induced oxidative stress could gradually lead to the currents of α4β2 nAChR run-down (P <0.01); the 450 kU/L of catalase (CAT) could prevent the currents running down (P <0.01). Conclusion The GO-induced oxidative stress could cause α4β2 nAChR currents gradually run down. ROS may play an important role in the current run-down of α4β2 nAChR.

Key words: reactive oxygen species, oxidative stress, nicotinic acetylcholine receptor