去甲肾上腺素在觉醒肽促醒酒精性昏迷大鼠中的作用

Role of noradrenaline in wake promotion effect of orexin-A on alcohol coma in rats

目的探讨去甲肾上腺素能系统是否参与觉醒肽(orexin-A)对酒精性昏迷大鼠的促醒作用。方法 24只成年雌性SPF级SD大鼠随机分为4组(n=6),建立酒精昏迷大鼠模型后,分别向大鼠侧脑室内注射人工脑脊液(ACSF,对照组)、觉醒肽(orexin-A)、去甲肾上腺素α1受体阻断剂哌唑嗪(prazosin)及prazosin+orexin-A。以大鼠翻正反射消失(LORR)持续时间和皮层脑电图δ波比例评判昏迷程度。结果与对照组相比,给予prazosin后大鼠LORR时间明显延长,δ波比例明显升高(P<0.01);而给予orexin-A后大鼠LORR时间明显缩短,δ波比例明显下降(P<0.01)。给予prazosin预处理后再给予orexin-A,大鼠LORR持续时间和δ波比例与对照组比较差异无统计学意义(P>0.05),与单纯给予orexin-A的大鼠比较差异有统计学意义(P<0.01),LORR持续时间和δ波比例并未因orexin-A的应用而缩短或降低。结论 Orexin-A可能通过对去甲肾上腺素能系统的兴奋起到对酒精性昏迷大鼠的促醒作用。

Objective To study whether or not noradrenaline system participates in the process of orexin-A wake- promoting from alcohol coma. Methods Twenty-four adult female SPF SD rats were divided into four groups, 6 each, and the model of alcohol coma was reproduced. Experimental rats were then divided randomly into rats receiving injection of artificial cerebrospinal fluid （ACSF, control group）, orexin-A （orexin-A group）, noradrenaline cx1 receptor antagonists-prazosin （prazosin group）, or prazosin ＋ orexin-A （prazosin-orexin-A group） into the lateral ventricle. The depth of coma was evaluated by the duration of loss of righting reflex （LORR） and wave in electrocorticogram （ECoG）. Results The duration of LORR was significantly longer and the ratio of 8 wave higher in the prazosin-treated rats than those in control group （P〈0.01）. Both of the duration of LORR and the ratio of 8 wave in ECoG were the same between the control group and the rats treated with prazosin ＋ orexin-A （P〉0.05）. But the values were significantly different from those in the orexin-A group （P〈0.01）. Conclusion Noradrenaline system may participate in the wake-promoting process of alcohol coma by orexin-A.