The influence of ketamine on KCC2 in spinal cord of rat in remifentanil-induced hyperalgesia / 中华行为医学与脑科学杂志

ABSTRACT

Objective To explore the effect of pre-treatment of subcutaneous injection of ketamine on remifentanil induced hyperalgesia and K+/Cl-cotransporter 2,KCC2) expression on spinal cord of rats.Methods60 male adult SD rats were randomly divided into five groups(n=12 in each group):control group (group C),the incision group(group I),the incision plus remifentanil group(group I+R),the incision plus ketamine group(group I+K) and the incision plus remifentanil and ketamine group(group I+R+K).Mechanical withdrawal threshold (MWT) was evaluated at 24 hours before incision(T0),2 hours,6 hours,24 hours and 48 hours after incision(T1~T4).The lumbar spinal cords of rats were taken out at T4 time point and the KCC2 detected was detected by immunofluorescence analysis and western blot analysis.ResultsCompared with group C(T1(14.5±1.7)g,T2(14.2±1.1)g,T3(13.9±1.8)g,T4(14.2±1.1)g),MWT of other groups at T1 (I(5.6±0.8)g,I+R(3.2±1.0)g,I+K(6.8±1.7)g,I+R+K(5.1±1.6)g),T2 (I(6.9±1.0)g,I+R(4.3±1.2)g,I+K(8.0±1.4)g,I+R+K(6.2±1.5)g),T3 (I(7.6±0.9)g,I+R(5.4±1.1)g,I+K(10.3±1.2)g,I+R+K(7.1±1.1)g),T4 (I(8.9±1.1)g,I+R(7.5±1.4)g,I+K(11.3±1.2)g,I+R+K(8.3±1.2)g)and the expression of KCC2 at T4 decreased (P<0.05).Compared with group I(T1(5.6±0.8)g,T2(6.9±1.0)g,T3(7.6±0.9)g,T4(8.9±1.1)g),MWT of group I+R (T1(3.2±1.0)g,T2(4.3±1.2)g,T3(5.4±1.1)g,T4(7.5±1.4)g) decreased at all time points after incision (T1~T4)(P<0.05) and the expression of KCC2 at T4 decreased significantly (P<0.05).Compared with group I(T1(5.6±0.8)g,T2(6.9±1.0)g,T3(7.6±0.9)g,T4(8.9±1.1)g),MWT of group I+K (T1(6.8±1.7)g,T2(8.0±1.4)g,T3(10.3±1.2)g,T4(11.3±1.2)g) increased at all time points after incision (T1~T4)(P<0.05) and the expression of KCC2 at T4 increased (P<0.05).Compared with group I+R(T1(3.2±1.0)g,T2(4.3±1.2)g,T3(5.4±1.1)g,T4(7.5±1.4)g),MWT of group I+R+K (T1(5.1±1.6)g,T2(6.2±1.5)g,T3(7.1±1.1)g,T4(8.3±1.2)g) increased at all time points after incision (T1~T4)(P<0.05) and the expression of KCC2 at T4 increased (P<0.05).ConclusionPre-treatment of subcutaneous injection of ketamine can reduce the hyperalgesia of rats induced by remifentanil and reduce the inhibition of KCC2 expression on dorsal horn of spinal cord.