Effect of L-838,417 on pain behavior in a rat model of trigeminal neuralgia / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of L-838,417 on the results of behavioral test in rats with experimentally induced trigeminal neuralgia.</p><p><b>METHODS</b>Male SD rats were randomized into model group (n=34), sham-operated group (n=30) and control group (n=6). Thirty rats with trigeminal neuralgia induced by chronic constriction injury of the infraorbital nerve below the zygomatic bone were randomly divided into 5 equal groups for treatment with 1.0 mg/kg L-838,417 (L1 group), 10.0 mg/kg L-838,417 (L10 group), 5 mg/kg morphine (M group), 3 mg/kg diazepam (D group), or normal saline (NS group). The pain threshold of the tentacles pad to von-Frey filament stimulation was measured in the rats before and at 1, 2, 3, 4, 5 h after the treatments. The sedative effect of L-838,417 was evaluated by recording the position scores and righting reflex scores, and the drug tolerance was also evaluated.</p><p><b>RESULTS</b>Nine days after the operation, the pain threshold of the rats in the model group was significantly decreased compared with that before operation and that of the sham group (P<0.01). The threshold of L1 and L10 groups were both significantly increased 1 h after L-838,417 administration (P<0.01). The rats in the NS, L1, and L10 groups did not show unusual posture or righting reflex. In L1 and L10 groups, L838,417 did not show attenuated efficacy after prolonged use (10 days).</p><p><b>CONCLUSION</b>L-838,417 can effectively improve hyperalgesia in rats with trigeminal neuralgia without causing sedation, motor impairment, or drug tolerance.</p>

Cerebral state index for monitoring sedation depth during target-controlled infusion with propofol and remifentanil / 第二军医大学学报

Objective:To examine the feasibility of using cerebral state index(CSI)for monitoring the sedation depth during target-controlled infusion(TCI)with propofol and remifentanil.Methods:Forty-four consenting ASAⅠorⅡpatients(aged 18-60 years)undergoing elective surgery under general anesthesia were randomly divided into 4 groups(n=11 each)according to the target effect-site concentrations of remifentanil administered by TCI during induction of anesthesia.The target effect-site concentrations of remifentanil of R_0,R_2,R_4,and R_6 groups were 0,2 ng?ml~(-1),4 ng?ml~(-1),and 6 ng?ml~(-1),respectively. Anesthesia was induced by TCI with remifentanil and propofol.CSI and bispectral index(BIS)were used to measure the sedation depth.The initial effect-site propofol concentration(PCe)was 1.5?g?ml~(-1),which was increased by 0.5?g?ml~(-1) every 4 min.The modified OAA/S score(5=alert,1=does not respond to prodding),loss of eyelash reflex(LOR eyelash)and loss of response to electric tetanie stimulation(LOR tetanic)were compared against CSI,BIS and PCe(calculated effect-site propofol concentration).Correlation coefficients were calculated between CSI and other parameters.Results:The 4 groups were comparable with respect to the ages and bodyweights.CSI and BIS values were higher but PCe value were lower at LOR eyelash and LOR tetanic in R_2,R_4,and R_6 than those in the R_0 group(P