Abstract: Objective To compare the effect of ropivacaine hydrochloride and (R)- ropivacaine hydrochloride on the human-ether-a-go-go-related gene(hERG) current in HEK293 cells that stably overexpress hERG potassium channels. Methods Manul patch clamp techniques were employed to investigate the effects of ropivacaine hydrochloride and (R)- ropivacaine hydrochloride on I_herg-tail in the HEK293 cell line that stably overexpresses hERG potassium channels. Results The inhibition rate of ropivacaine hydrochloride on hERG was (6.12±0.30)%,(13.04±1.20)%, (19.21±0.33)%, (35.56±0.66)% and (65.37±4.17)% at the doses of 0.37, 1.11, 3.33, 10.00 and 30.00 μmol·L^-1. The half-maximal inhibitory concentration (IC₅₀) of ropivacaine hydrochloride on hERG was 19.482 μmol·L^-1 (n=15). The inhibition rate of (R)- ropivacaine hydrochloride on hERG was (4.13±3.43)%, (7.34±5.60)%, (9.49±2.75)%, (16.60±0.87)% and (31.36±1.45)% at the doses of 30.00, 10.00, 1.11 and 0.37 μmol·L^-1. The half-maximal inhibitory concentration (IC₅₀) of (R)-ropivacaine hydrochloride on hERG exceeded 30 μmol·L^-1 (n=15). The inhibition rate of dofetilide on hERG was (7.81±2.77)%, (19.67±1.88)%, (57.16±4.39)%, (89.71±3.55)% and (99.66±0.89)% at the doses of 0.001 85, 0.005 56, 0.016 67, 0.050 00 and 0.150 00 μmol·L^-1. The half-maximal inhibitory concentration (IC₅₀) of dofetilide on hERG was 0.015 μmol·L^-1(n=15).Conclusion Compared with dofetilide, ropivacaine hydrochloride has weak inhibitory effect on the hERG channel and (R)- ropivacaine hydrochloride has no obvious inhibitory effect on the hERG channel.

Key words: ropivacaine hydrochloride, (R)-ropivacaine hydrochloride, amide local anesthetic, manual patch clamp method, HEK 293 cells, hERG potassium channel, stereoselectivity