Ghrelin对大鼠摄食选择的影响及机制

The effects of Ghrelin on food choice of rats

目的探讨Ghrelin对大鼠摄食选择的影响。方法24只大鼠随机数字表法分为对照组，0．1nMGhrelin组和1．0nMGhrelin组，每组8只。对照组大鼠侧脑室注射0．2txl人工脑脊液，后2组分别侧脑室注射0．1nM和1．0nM的Ghrelin0．2txl，观察大鼠摄食量、摄食启动、摄食可口度。侧脑室注射多巴胺D1受体拮抗剂SCH23390，观察Ghrelin影响大鼠摄食的机制。结果侧脑室注射Ghrelin，大鼠摄食量明显增加、摄食间隔时间明显缩短，且呈显著量效依赖关系（P〈0．05～0．01）；与普通流食组相比，大鼠摄取添加奎宁食物量明显降低[（16．73±5．21）ml与（23．47±9．46）ml，P〈0．01]，但侧脑室注射Ghrelin不能逆转该效应[（13．74±3．29）ml与（16．73±5．21）ml，P〉0．05]；侧脑室注射Ghrelin，大鼠摄取添加蔗糖的流食量明显增加，呈显著量效依赖关系（P〈0．05—0．01），且显著高于禁食大鼠的食物摄取量[（59．24±17．32）ml与（38．13±10．98）ml，P〈0．05]；侧脑室注射SCH23390，可使大鼠摄食量明显降低[（22．69±6．54）ml与（28．21±7．35）ml，P〈0．05]，若侧脑室注射SCH23390＋Ghrelin，Ghrelin促进大鼠摄食作用明显减弱[（32．44±10．62）ml与（65．81±13．47）ml，P〈0．05]。结论Ghrelin可影响大鼠食物选择，多巴胺可能参与了该过程的调控。

Objective To study the effect of Ghrelin on food choice of rats. Methods Twenty-four Wist- ar rats were randomly divided into control group ,0.1 nM Ghrenlin group and 1.0 nM Ghrenlin group, and 8 rats in each group. 0.2 μl arificial cerebrospinal fluid were injected into the lateral ventricle in control group, and the same volume 0. lnM and 1.0 nM Ghrelin were done in 0.1 nM Ghrenlin group and 1.0 nM Ghrenlin group respectively. The changes of food intake, feeding interval, and torlerance of different flavors of food intake were observed. The SCH23390, an antagonist of dopamine D1 receptor, was used to explore the mechanisms of Ghrelin. Results The rats＇ food consumption increased significantly and the intake intervals reduced dose dependently after injecting Gh- relin into the lateral ventricles （ P〈0.05 - 0.01 ）. Compared with nomlal liquid food,the rats＇ intake of food added with quinine was reduced（（16.73±5.21） ml vs （23.47±9.46）ml, P〈0.01 ） , and injecting Ghrelin into the lateral ventricles could not reverse this effect （（13.74±3.29） ml vs （16.73±5.21）ml, P〉0.05）. After injecting Ghrelin, the rats＇ intake of liquid food added with sugar increased in a dose dependent manner（ P〈0.05 - 0.01 ） , and higher than the food intake of fasted rats （ （ 59.24± 17.32） ml vs （ 38.13± 10.98 ） ml, P〈0.05 ）. The food intake reduced obviously after injecting SCH23390 （ （22.69±6.54）ml vs （28.21±7.35）ml, P〈O.05）. But the rats＇ food intake was significantly lower after injecting SCH23390 ＋ Ghrelin than the rats only injected of Ghrelin （（32.44±10.62）ml vs （65.81±13.47）ml, P〈0.05）. Conclusion Ghrelin can affect the food choice of rats ,and dopamine may be involved in the regulation of this process.