瘦素对快速动眼睡眠剥夺大鼠焦虑行为的影响及其机制探讨

摘要

Objective To observe the effects of leptin on the anxiety behavior in REM sleep deprived rats, and to ex-plore its mechanisms.Methods A total of 90 male Wistar rats were randomly divided into 9 groups on average, as fol-lows:living together in home cage ( NS group) for 24, 72 and 120 h with NS,REM sleep deprived for 24,72 and 120 h with leptin ( L-SD group) or with NS ( NS-SD group) .The single platform ( SP) method was used to build the REM sleep deprivation model;the elevated plus-maze ( EPM) was used to assess the anxiety behavior;the RT-PCR method was used to measure the level of neuropeptide Y ( NPY) mRNA.Results At 24 h and 120 h, numbers of open arm ( OE) +closed arm (CE) in NS-SD and L-SD groups was higher than that in NS group (all P<0.01);the difference of OE+CE among 3 groups was not significant (P=0.47).At 120 h, compared with NS, OE ratio (OE%) and stay open arm ratio (OT%) increased in NS-SD group, but decreased in L-SD group, all P<0.01.At 120 h time point, OE%and OT%in NS-SD group were higher than those in 24 h and 72 h;but OE%and OT%at 120 h in L-SD group were lower than those in 24 h and 72 h;all P<0.01.Compared with NS group at the same time, NPY mRNA level in hypothalamus in NS-SD and L-SD groups increased (P<0.05 or P<0.01).At 24 h, 72 h, 120 h, NPY mRNA in NS-SD group increased gradu-ally, which in L-SD group decreased gradually, all P<0.05.Conclusion Chronic REM sleep deprivation could decrease the anxiety behavior in rats, but leptin could eliminate this effect;leptin inhibited the expression of NPY in hypothalamus might be one of its mechanisms.%目的：观察瘦素对快速动眼（ REM）睡眠剥夺大鼠焦虑行为的影响，并探讨其机制。方法采用随机数字分布表法将大鼠分为3组，每组30只，分别为L-SD组、NS-SD组、NS组，根据处理时间不同每组再分为3个亚组各10只。 NS-SD组、L-SD组置入REM睡眠剥夺小平台中，使其始终不能进入REM睡眠期，分别于睡眠剥夺24、72、120 h腹腔注射生理盐水2 mL／d、瘦素200μg／d（2 mL／d）；NS组分别于正常群居24、72、120 h腹腔注射生理盐水2 mL／d。高架十字迷宫（ EPM）测试大鼠焦虑行为，RT-PCR法检测下丘脑神经肽Y（ NPY） mRNA。结果24、120 h时，NS-SD、L-SD组开放臂次数（ OE）＋封闭臂次数（ CE）均高于NS组，P均＜0．01；72 h时，3组间OE＋CE差异无统计学意义（P＝0．47）。120 h时，与NS组比较，NS-SD组OE比例（OE％）、开放臂停留时间比例（OT％）增加，L-SD组OE％、OT％减少，P均＜0．01；120 h时NS-SD组OE％、OT％高于24、72 h，P均＜0．01；24、72 h时L-SD组OE％、OT％高于120 h，P均＜0．01。与相同时间点NS组比较，NS-SD组下丘脑组织NPY mRNA表达量均增加，且随时间增加表达量逐渐增加，P均＜0．05；L-SD组大鼠下丘脑NPY mRNA表达量随时间增加逐渐下降，P均＜0．05。结论长期REM睡眠剥夺可导致大鼠焦虑行为减少，而瘦素可抑制上述作用；抑制下丘脑组织NPY mRNA表达，可能是瘦素的作用机制之一。