雷莫司琼降低幼鼠内脏痛觉敏感性

目的:采用行为学和电生理学评价方法,探讨应用5-羟色胺3(5-HT3)受体拮抗剂雷莫司琼对幼鼠内脏痛觉敏感性影响。方法:新生期反复结直肠刺激(colorectal irritation,CI)建立幼鼠内脏痛觉高敏感性模型。32只SD新生大鼠按2×2析因设计分成4组,每组8只,A1B1组:新生期反复CI,15～21d腹腔注射雷莫司琼;A1B2组:新生期反复CI,15～21d腹腔注射生理盐水;A2B1组:新生期未接受CI,15～21d腹腔注射雷莫司琼;A2B2组:新生期未接受CI,15～21d腹腔注射生理盐水。常规饲养到幼鼠期(6周龄),通过观察幼鼠在不同压力结直肠扩张(colorectaldistension,CRD)刺激后的腹壁撤退反射(AWR)评分、内脏痛阈和腹外斜肌放电测量进行内脏痛觉敏感性评价。结果:幼鼠痛阈受建立内脏痛敏化模型和早期雷莫司琼干预两因素影响。建立内脏痛敏化模型可使幼鼠痛阈降低11.56mm Hg,早期雷莫司琼干预则使幼鼠痛阈提高9.06mm Hg,两者存在交互作用。应用雷莫司琼使AWR评分及腹外斜肌放电幅值降低,对于AWR评分的主效应在各个CRD压力下有统计学意义;对腹外斜肌放电幅值的主效应在各不同CRD压力下亦有统计学意义。结论:应用5-HT3受体拮抗剂雷莫司琼能够降低幼鼠内脏痛觉的高敏感性。

Ramosetron decrease visceral pain hypersensitivity in young rats

AIM： To explore the effects of 5-HT3 receptor antagonist ramosetron on young rats of visceral hypersensitivity by the methods of behavior and electrophysiology research.METHODS： Colorectal irritation（CI） stimulation in neonatal period was used to establish the model of visceral hypersensitivity in young rats.32 neonatal rats were divided into four groups by 2×2 factorial design with each 8.Group A1B1 was imposed on CI at neonatal period and imposed on ramosetron intraperitoneal injection in 15-21 day;Group A1B2 was imposed on CI at neonatal period and not imposed on ramosetron intraperitoneal injection;Group A2B1 was not imposed on CI at neonatal period and imposed on ramosetron intraperitoneal injection;Group A2B2 was not imposed on CI at neonatal period and not imposed on ramosetron intraperitoneal injection.Then,conventionally breeding till the young period（6-week age）,abdonminal withdrawal reflex（AWR）,pain thresholds and spike external oblique muscle of abdomen（EOMA） were used to evaluate visceral pain hypersensitivity.RESULTS：he pain thresholds in young rats were affected both by CI at neonatal period and using ramosetron in 15-21 days.In group A1B2 which imposed on CI at neonatal period,the pain thresholds decreased 11.56 mm Hg.In group A1B1 which imposed on CI at neonatal period and imposed on ramosetron in 15-21 day,the pain thresholds increased 9.06 mm Hg,while the AWR scores and EOMA were decreased.Future more,there are interaction effects between the two factors.There were a significant main effect for AWR scores at different pressures and a significant main effect for EOMA at different pressures.CONCLUSION： 5-HT3 receptor antagonist ramosetron can decrease visceral hypersensitivity in young rats.