睡眠中间断低氧对大鼠下丘脑-垂体-肾上腺轴和生长激素的影响

目的:探讨睡眠中间断低氧对大鼠下丘脑-垂体-肾上腺轴和生长激素水平的影响.方法:大鼠分别给予吸入空气,持续低氧和间断低氧气体,在1 d,3 d,7 d和30 d后测定下丘脑促肾上腺皮质激素释放激素(CRH)和生长激素释放激素(GHRH)mRNA水平,并测定30d后血浆CRH,GHRH,促肾上腺皮质激素(ACTH)和皮质酮水平,分析其间的变化关系.结果:与对照组比较,在低氧后1 d,3 d,7 d后大鼠下丘脑CRH mRNA升高,GHRH mRNA降低,在30 d后,间断低氧组下丘脑CRH mRNA升高,GHRH mRNA降低,而持续低氧组则接近正常.间断低氧30 d后,血浆CRH、ACTH,皮质酮均升高,GHRH降低,而生长激素没有明显变化.结论:大鼠睡眠中慢性间断低氧可以引起下丘脑-垂体-肾上腺轴激素水平升高,反馈调节紊乱,可引起GHRH分泌抑制.

The effect of chronic intermittent hypoxia to hypothalamus-pituitary-adrenal axis and growth hormone level in rats during sleep

Aim: To research the effect of intermittent hypoxia during sleep on hypothalamus-pituitary-adrenal(HPA) axis and growth hormone(GH) level.Methods: Rats were respectively exposed to intermittent hypoxia,room air and continuous hypoxia,after 1 day,3 days,7 days and 30 days,mRNA levels of corticotropin-releasing hormone(CRH) and growth hormone releasing hormone(GHRH) in hypothalamus of rats were detected using RT-PCR,and the levels of CRH,GHRH,corticotropin(ACTH),cortex ketone,and growth hormone in plasma were measured.Results: After 30 days,the CRH mRNA levels in rats hypothalamus which exposed to intermittent hypoxia were increased significantly than those exposed to continuous hypoxia as well as normal control but GHRH decreased,there was no difference between continuous hypoxia and normal control.After 1 day,3 days,and 7 days,there was no difference between continuous hypoxia and intermittent hypoxia.After 30 days,the plasmic level of CRH,ACTH and cortex ketone increased,GHRH decreased and GH had no obvious change.Conclusion: The rats' HPA axis level increses and GHRH restraines with chronic intermittent hypoxia during sleep,feedback regulation disorders.