Orexin A对慢性间歇低氧大鼠颏舌肌长时程易化的影响

Regulation of Orexin A on Long-term Facilitation of Genioglossus in Rats

目的:探讨慢性间歇低氧(CIH)对大鼠颏舌肌长时程易化(LTF)的影响和Orexin A/Orexin A受体拮抗剂对慢性间歇低氧大鼠颏舌肌长时程易化的调控。方法:30只合格成年大鼠采用随机数字表法随机分为6组,每组5只:常氧对照组,慢性间歇性低氧组,生理盐水组,Orexin A低浓度组,Orexin A高浓度组,Orexin A受体拮抗组,后5组大鼠放置于慢性间歇低氧动物仓中,常氧对照组放置于常氧动物仓中,每天8h,连续4周。最后给各组大鼠大脑中缝背核分别注射生理盐水(0.1μl),低浓度Orexin A(50nmol,0.1μl),高浓度Orexin A(100μmol,0.1μl)和Orexin A受体拮抗剂(10μmol,0.1μl),分别记录其颏舌肌放电幅度。结果:慢性间歇低氧组颏舌肌放电幅度较常氧对照组明显增强(P<0.05,n=5),生理盐水组颏舌肌放电幅度较慢性间歇低氧组无明显变化(P>0.05,n=5)。Orexin A低浓度组和Orexin A高浓度组颏舌肌放电幅度较慢性间歇低氧组均有增强(P<0.05,n=5),且与药物浓度成正比。Orexin A受体拮抗剂组颏舌肌放电幅度较慢性间歇性低氧组有所降低(P<0.05,n=5)。结论:慢性间歇低氧可诱导大鼠颏舌肌长时程易化,Orexin A/Orexin A受体拮抗剂对慢性间歇低氧大鼠颏舌肌长时程易化有具有调控作用:Orexin A可增强慢性间歇低氧大鼠颏舌肌长时程易化,且与药物浓度成正比;Orexin A受体拮抗剂可减弱慢性间歇低氧大鼠颏舌肌长时程易化。

Objective：To explore the impact of chronic intermittent hypoxia（CIH）on long-term facilitation（LTF）of the SD rat＇s genioglossus and the regulation of Orexin A/Orexin A receptor antagonists on long-term facilitation of the SD rat＇s genioglossus.Methods：Thirty qualified adult rats were divided into 6groups（n=5）by the random number table：normoxic control group,CIH group,normal saline group,Orexin A low concentrations group,Orexin A high concentrations group,and Orexin A receptor antagonists group;the last 5groups were fed in the chronic intermittent hypoxia animal chambers,while the normoxic control group was placed in the normoxia animal chambers for 8hper day for 4consecutive weeks.After that,the dorsal raphe nucleus of the SD rats were injected with normal saline（0.1μl）,Orexin A（50nmol,0.1μl）,OrexinA（100nmol,0.1μl）,and Orexin A receptor antagonists（10μmol,0.1μl）respectively,the discharge magnitude of genioglossus were recorded.Results：The discharge magnitude of genioglossus in CIH group was much higher than in normoxic control group（P〈0.05,n=5）,the discharge magnitude of genioglossus in normal saline group was almost the same than in the CIH group（P〈0.05,n=5）.The discharge magnitude of genioglossus in Orexin A low concentrations group and Orexin A high concentrations group were higher than in CIH group（P〈0.05,n=5）,this enhancement was proportional to the drug concentration.The discharge magnitude of genioglossus in Orexin A receptor antagonists group was lower than that in CIH group（P〈0.05,n=5）.Conclusion：Chronic intermittent hypoxia can induce LTF of the SD rat＇s genioglossus,Orexin A/Orexin A receptor antagonists plays a regulatory role for LTF of the SD rat＇s genioglossus.Orexin A can enhance the LTF of the SD rat＇s genioglossus,this enhancement is proportional to the drug concentration;Orexin A receptor antagonists can weaken the LTF of the SD rat＇s genioglossus.