第四脑室注射Orexin-A对大鼠饮食摄取条件性位置偏爱的影响

Effect of Fourth ICV SB334867 on Food-conditioned Place Preference in Rats

目的:探讨第四脑室注射orexin-A(OXA)对大鼠饮食摄取条件性位置偏爱的影响。方法:将30只大鼠随机分成3组,即对照组,低剂量组和高剂量组,第四脑室分别注射生理盐水(NS)、orexin-A或orexin-A受体拮抗剂SB334867,观察大鼠按压杠杆获取蔗糖的次数和最高频率的变化。再选择30只大鼠,第四脑室注射orexin-A和SB334867,观察大鼠对高脂饮食(HF)食物的摄入量。另选取30只大鼠第四脑室注射orexin-A或SB334867,将大鼠置于条件位置偏爱箱来检测大鼠对HF条件性位置偏爱的变化。结果:与对照组相比,24小时禁食大鼠,第四脑室注射orexin-A,可显著增加大鼠按压杠杆获取蔗糖的次数和最高频率(P<0.05)。而SB334867可显著降低大鼠按压杠杆获取蔗糖次数以及最大频率(P<0.05)。第四脑室注射orexin-A,可使大鼠HF摄入量显著增加(P<0.05),第四脑室注射SB334867,不影响大鼠HF摄入量,但会抑制普通饮食的摄入(P<0.05)。第四脑室注射orexin-A能增强对HF饮食位置偏爱性的表达,注射SB334867后会显著抑制大鼠对HF饮食位置偏爱性的表达(P<0.05)。结论:第四脑室注射Orexin-A可影响大鼠摄食行为,增加高脂饮食的摄入量,增强对HF饮食位置偏爱性的表达。

Objective： To investigate the effects of the fourth ventricle injection of orexin-A（OXA） on food-conditioned place preference in rats. Methods： 30 SD male rats were randomly divided into three groups： the control group, low-dose group and high-dose group. The fourth ventricle were injected with saline（NS）, orexin-A or orexin-A receptor antagonist SB334867, observed changes of sucrose lever presses and breakpoint of rats. Then selecting 15 rats with fourth ventricle injection orexin-A or SB334867 was observed the effects on HF food intake during daily 1-h tests. At last, 30 rats with fourth ventricle injection orexin-A or SB334867, the rats were placed in conditioned place preference box to detect expression of the place preference of rats with HF food. Results： Compared with the control group, after 24 hours of fasting, The sucrose lever presses and breakpoint of rats were significantly increased through fourth ventricle injection of orexin-A（P〈0.05）. But SB334867 significantly reduced sucrose lever presses and breakpoint（P〈0.05）. The HF intake of rats was significantly increased with fourth ventricle injection of orexin-A（P〈0.05）, while SB334867 did not affect the HF intake, however SB334867 would inhibit chow intake（P〈0.05）. The expression of HF food-conditioned place preference of rats was enhanced through fourth ventricle injection of orexin-A, while SB334867 inhibited this effect（P〈0.05）. Conclusions： The Fourth ventricle injection of Orexin-A may affect feeding behavior in rats, increase the intake of HF food, and enhance the expression of HF food-conditioned place preference.