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.
ABSTRACT
Objective To evaluate the effect of verapamil on the expression of K+-Cl-cotransporter 2 (KCC2) in spinal dorsal horns during remifentanil-induced hyperalgesia in a rat model of incisional pain.Methods Thirty-two pathogen-free healthy adult male Sprague-Dawley rats,aged 6-7 weeks,weighing 250-300 g,were divided into 4 groups (n=8 each) using a random number table:control group (group C),incisional pain group (group Ⅰ),incisional pain plus remifentanil plus verapamil group (group I+R+ V) and incisional pain plus remifentanil group (group I+R).Normal saline was subcutaneously infused in group C.A 1 cm long incision was made in the plantar surface of the right hindpaw in anesthetized rats in group Ⅰ.Verapamil 5 mg/kg was intraperitoneally injected at 10 min before establishment of the incisional pain model in group I+R+V.In I+R and I+R+V groups,the model of incisional pain was established,and remifentanil was subcutaneously infused for 30 min at a rate of 80 μg · kg-1 · h-1 simultaneously.The mechanical paw withdrawal threshold (MWT) to yon Frey filament stimulation was measured at 1 day before establishment of the model (T0) and 2,6,24 and 48 h after establishment of the model (T1-4).The rats were sacrificed after measurement of MWT at T4,and the lumbar enlargement segments of the spinal cord were harvested for determination of the expression of KCC2 by immunofluorescence.Results Compared with group C,the MWT was significantly decreased at T1-4,and the expression of KCC2 was down-regulated in the other groups (P＜0.05).Compared with group Ⅰ,the MWT was significantly decreased at T1-4,and the expression of KCC2 was down-regulated in group I+R (P＜0.05).Compared with group I+R,the MWT was significantly increased at T1-4,and the expression of KCC2 was up-regulated in group I+R+V (P＜0.05).Conclusion The mechanism by which verapamil reduces remifentanil-induced hyperalgesia is related to up-regulation of the expression of KCC2 in spinal dorsal horns in a rat mnodel of incisional pain.
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Objective To investigate the inter-arm invasive blood pressure differences during hip replacement in patients with lateral position and its relationship with position.Methods Sixty-six patients having underwent hip replacement in orthopedic surgery with lateral position were enrolled.Invasive blood pressure measurements were obtained from bilateral radial artery in all patients every 5 minutes.Simultaneously bilateral invasive blood pressure measurements were obtained and compared.Results At supine position,systolic pressure,diastolic pressure and mean arterial pressure of the uninjured side were (128.16 ±20.09),(69.47 ± 8.64) and (89.03 ± 10.42) mmHg (1 mmHg =0.133 kPa);systolic pressure,diastolic pressure and mean arterial pressure of the injured side were (127.90 ± 20.44),(69.86 ± 8.81) and (89.21 ± 10.71) mmHg.There was statistical difference in inter-arm diastolic pressure (P ＜ 0.05),but inter-arm systolic pressure and mean arterial pressure had no statistical differences (P ＞ 0.05).At left-lateral position,systolic pressure,diastolic pressure and mean arterial pressure of the uninjured side were (129.12 ± 21.93),(69.23 ± 8.92) and (89.19 ± 11.35) mmHg;systolic pressure,diastolic pressure and mean arterial pressure of the injured side were (129.01 ± 21.72),(69.51 ± 9.02) and (89.34 ± 11.35) mmHg.There was statistical difference in inter-arm diastolic pressure (P ＜ 0.05),but inter-arm systolic pressure and mean arterial pressure had no statistical differences (P ＞ 0.05).At right-lateral position,systolic pressure,diastolic pressure and mean arterial pressure of the uninjured side were (128.78 ± 20.34),(69.54 ± 9.06) and (89.29 ± 10.82) mmHg;systolic pressure,diastolic pressure and mean arterial pressure of the injured side were (128.27 ± 20.56),(70.00 ± 9.09) and (89.43 ± 10.89) mmHg.There were statistical differences in inter-arm systolic pressure and diastolic pressure (P ＜ 0.05),but inter-arm mean arterial pressure had no statistical difference (P ＞ 0.05).The bilateral radial artery blood pressure difference under different positions was ＜ 1 mmHg,and had no clinical practical significance.There was no correlation between blood pressure and age,sex,body mass index.Conclusion Bilateral radial artery in the same patients with invasive blood pressure has no clinical difference,and patients with lateral position operation for radial artery puncture pressure need not consider the differences of blood pressure between arms.