The antagonist of TRPV1 attenuates cytotoxicity of DRG neurons induced by lidocaine / 临床麻醉学杂志

ABSTRACT

Objective To determine whether or not capsazepine(CPZ),a transient receptor po-tential vanilloid-1(TRPV1)antagonist,attenuates lidocaine-induced cytotoxicity on rat dorsal root ganglion (DRG)neurons in vitro.Methods Adequate DRG neurons from 3-day neonatal Wistar rats were obtained,cultured and purified in vitro.To achieve higher cell viability,we reduced the concen-tration of trypsin to 0.125% compared with others.The purified DRG neurons were incubated with 0,2.5,5,10,20 and 40 mmol/L lidocaine for 10 min,respectively,their viabilities were examined using Cell Counting Kit(CCK-8)assay,and the lethal concentration 50(LC50 )of lidocaine on DRG neurons was calculated.Then,the variation of lidocaine-induced cell viability at LC50 ,when 0,1,10 and 100 μmol/L CPZ were respectively added to the incubations,was examined with CCK-8 assay. Results The purified percentage of DRG neurons was as high as 91% after digesting by 0.125%trypsin and purifying in vitro.Cell viability of DRG neurons in group L1,L2,L3,L4,L5 was signifi-cantly down regulated compared with the control group,to be specific,that of L3,L4,L5 being re-markably lower than that of L1,that of L4,L5 lower than that of L2 and that of L5 lower than that L3 and L4.After lidocaine induced DRG neurons for 10 min,LC50 was 30 mmol/L;10 μmol/L and 100 μmol/L CPZ significantly reduced LC50 DRG neuron toxicity induced by lidocaine (P <0.05). The effect of 10 μmol/L CPZ had reached the maximal effect,decreasing the cell viability decrease from 50% to 35%.Conclusion The novel method in this experiment is effective to obtain good DRG neurons,the LC50 of lidocaine on rat DRG neurons is 30 mmol/L,and CPZ attenuates the cytotoxicity induced by lidocaine on rat DRG neurons.