Objective To investigate the role of neurokinin-1 receptor (NK-1R) in the anti-nociceptive effect of enflurane, isoflurane and sevoflurane in mice. Methods Three hundred and twenty Kunming mice of both sexes weighing 20-25 g were randomly divided into4 groups (n =80 each): group normal saline (group NS);group enflurane (group E); group isoflurane (group I) and group sevoflurane (group S). Normal saline (NS) 1.0ml/kg, erflurane 0.5 ml/kg, isoflurane 0.4 ml/kg and sevoflurane 2.0 ml/kg were injected intraperitoneally in NS,E,I and S groups respectively. Each group was further divided into 4 subgroups receiving intrathecal NS 5 μl and Sar-SP (NK-IR agonist) 20, 40 and 80 ng respectively at 5 min after intraperitoneal injection of inhalation anesthetics. The anti-nociceptive effect of the inhalation anesthetics was assessed by tail flick latency (TFL) (the latency for removal of the tail from the path of heat source) and paw-licking time (PLT) after intraplantar formalin injection. Results lntraperitoneal enflurane, isoflurane and sevoflurane significantly prolonged TFL and shortened PLT. Intrathecal Sar-SP 20, 40 and 80 ng significantly shortened TFL dose-dependently but had no significant effeet on PLT as compared with control subgroup. Conclusion NK-1R is involved in the anti-nociceptive effect of enflurane, isoflurane and sevofluran on thermal pain but not chemical and inflammatory pain.

ObjectiveTo explore the effects and underlying mechanisms of acid sensing ion channels (ASICs) on pain behavior in a rat model of post-incision pain.MethodsFifty-eight adult male Sprague Dawley rats were used in this study,four rats were used for immunofluorescence test,thirty rats were employed for pain behavior test,and twenty-four rats were used for Western blot.Rats used for pain behavior test and Western blot were randomly divided into 3 groups:control group ( C group),incision pain model group ( I group) and amiloride group (A group).Plantar skin of rats in A group were infiltrated with 20 μl(200 μg)amiloride solution.Paw withdrawal mechanical threshold(PWMT) and paw withdrawal thermal latency(PWTL) of all rats in pain behavior test was tested at 24 h preoperative,2 h,4 h,8 h,12 h,24 h postoperative.Western blot was tested at 4 h postoperative.ResultsImmunofluorescence test displayed ASIC3 was expressed in plantar skin of all rats.The basal level of PWMT and PWTL of all rats in three groups was C group( (23.15 ± 5.10) g,( 11.32 ± 1.21 ) s),I group ( (23.26 ± 5.69) g,( 11.75 ± 2.01 ) s),A group ( (23.63 ± 4.96 ) g,( 11.47 ± 1.96) s) respectively,which was no significantly difference (P ＞ 0.05 ).PWMT and PWTL of I group and A group was significantly lower than that of C group at all time points postoperative (P ＜ 0.05) ; PWMT and PWTL of A group was at 2 h( ( 13.75 ±3.25)g,(9.96±1.32)s),4h((14.05±3.75)g,(9.17±2.11)s),8 h((9.75 ±2.74)g,(8.11 ±1.22)s)postoperative,which was significantly higher than that of I group (P ＜ 0.05 ).Compared with that of C group,the level of pERK1/2 expression was significantly increased in I group at 4 h postoperative (P ＜ 0.05 ),which could be inhibited by amiloride local infiltration (P ＜ 0.05 ).ConclusionASIC3 can mediate incision pain in a rat model of post-incision pain,through pERK1/2 signaling pathway,which can be inhibited by amiloride.

To study the anticancer effects of tea polyphenols on colorectal cancer with microsatellite instability (MSI) in nude mice and to explore its mechanism.