腹腔注射小剂量氯胺酮对小鼠吗啡诱发急性瘙痒的影响

Effect of the low-dose intraperitoneal ketamine on acute morphine-induced scratchingin mouse

目的观察小剂量氯胺酮对小鼠吗啡诱发急性瘙痒的作用。方法40只雄性C57／BL6小鼠按完全随机分组方法分为5组（每组8只）：空白对照组（C组），鞘内注射生理盐水5μl；吗啡组（M组），鞘内注射1．0nmol吗啡5μl；生理盐水对照组（N组），鞘内注射1．0nmol吗啡5m，5min后腹腔注射5mg／kg生理盐水；氯胺酮给药组（K组）：鞘内注射1．0nmol吗啡5μl，5±in后腹腔注射5g，L氯胺酮；氯胺酮对照组（KC组）：鞘内注射5μl生理盐水后腹腔注射5g/L氯胺酮。以5min为间隔记录小鼠40min内搔抓次数。结果与C组比较，M组小鼠搔抓次数明显增加，0—5min小鼠开始出现搔抓反应[（5．0±1．2）次]，6min～10min搔抓反应达到高峰期[（13．1±1．9）次]，随后减少，持续约40min；与N组比较，K组搔抓次数在6min-10min[（4．8±1．4）次]、1lmin～15min[（4．1±1．2）次]、16min-20min[（2．2±0．7）次]均有不同程度的下降（P〈0．05）；与KC组比较，K组搔抓次数除31min--40min外，差异均有统计学意义（P〈0．05）。腹腔注射氯胺酮后K组搔抓次数明显减少（P〈0．05）。结论腹腔注射小剂量氯胺酮能在一定程度上缓解小鼠吗啡诱发的急性瘙痒。

Objective To investigate the effect of low-dose intraperitoneal ketamine administration on acute morphineinduced scratchingin in mouse. Methods Forty male C57/BL6 mice were randomly divided into 5 groups （n=8）： control group （group C）, physiological saline group（group N）,morphine group（group M）, ketamine treatment group（group K）, ketamine group （group KC）. Group C and group M intrathecal of 5 μl saline or morphine（ 1.0 nmol）, group N and group K intrathecal of morphine 5 min after intraperitoneal injection of ketamine （5 g/L）, group KC intraperitoneal injection of ketamine （5 g/L）. Observate and record hindpaw scratching behavior every 5 min within 40 min. Results Compared with group C, the number of scratching bouts had significantly increased, in group M, in 0-5 min （5.0±1.2） mice began to scratching, 6 min-lO min （13.1±1.9） scratching bouts reached its peak, and then decreased, which lasted about 40 min. Compared with group M, scratching bouts in 6 min-10 min （4.8± 1.4）, 11 min-15 min （4.1±1.2）, 16 min-20 min （2.2±0.7） rain in group K declined to have the statistical significance （P〈O.05）, compared with group KC, scraching bouts in group K had statistical difference except 31 min-40 min. While after intraperitoneal injection of ketamine, total number of bouts were significant decreased in group K（P〈0.05）. Conclusions Intraperitoneal injection of low-doses of ketamine relieving intrathecal morphine-induced scratching to a certain extent.