Effects of ropivacaine on sodium, calcium, and potassium currents in guinea pig ventricular myocytes.
OBJECTIVE
To study the effects of ropivacaine (Rop) on sodium current (INa), L-type calcium current (ICa-L), inward rectifier potassium current (IK1), and delayed rectifier potassium current (IK) in isolated guinea pig ventricular myocytes.


METHODS
Whole cell patch-clamp techniques were used in our experiment.


RESULTS
At potential of -40 mV, Rop 10, 50, and 100 micromol/L decreased sodium current by 8.3 %, 33.3 %, and 62.5 %, respectively and prolonged the time constant of INa inactivation by 8.2 %, 24.7 %, and 64.4 %, respectively (n = 5 cells from 3 animals, P < 0.05). At potential of +10 mV, Rop 50 and 100 micromol/L decreased L-type calcium current by 7.6 % and 22.5 %, and prolonged the slow time constant of ICa-L inactivation by 15.5 % and 33.0 %, respectively (n = 5 cells from 4 animals, P < 0.05). Rop 50 and 100 micromol/L did not markedly change the peak current of delayed rectifier potassium current and inward rectifier potassium current (n = 5 cells from 3 animals, P > 0.05), respectively.


CONCLUSIONS
Rop depressed INa and ICa-L, which may be related to its cardiotoxic effect
Ding
Hai-Lei
HL
Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical College, Xuzhou 221002, China. hailei0314@263.net
Zeng
Yin-Ming
YM
Li
Xiao-Dong
XD
Jiang
Wen-Ping
WP
Duan
Shi-Ming
SM
D000577:Amides / Q000494:pharmacology*; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D002469:Cell Separation; D006168:Guinea Pigs; D006352:Heart Ventricles / Q000166:cytology; D032342:Muscle Cells / Q000187:drug effects* / Q000378:metabolism; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000378:metabolism*; D000077212:Ropivacaine; D015222:Sodium Channels / Q000378:metabolism*
D000577:Amides; D000779:Anesthetics, Local; D020746:Calcium Channels, L-Type; D015221:Potassium Channels; D015222:Sodium Channels; D000077212:Ropivacaine