饥饿大鼠脑杏仁核中瘦素受体的表达(英文)

Expression of leptin receptor in the cerebral amygdala of starved rats

背景:饥饿是脂肪代谢的一个重要过程,可触发适应性反应,瘦素水平下降,但饥饿时脑中瘦素受体是否变化及变化情况尚不清楚。目的:饥饿状态下瘦素受体表达的变化及杏仁基底外侧核和中央核的作用。设计:随机对照的实验研究。地点和材料:实验地点:西安交通大学医学院。成年健康雄性SD大鼠20只,随机分为禁食24,48,72h组和对照组,每组5只。干预措施:各组大鼠禁食前后分别检测体质量,体长,尾长。采用放免法测定血清瘦素水平,免疫组化ABC法检测瘦素受体和神经细丝酸性蛋白(glialfibrillaryacidicprotein,GFAP)的表达情况。主要观察指标:①各组大鼠体质量减少量,Lee指数,血清瘦素水平和血糖水平。②各组大鼠瘦素受体的表达。③各组大鼠星形胶质细胞GFAP的表达。结果:禁食24h血清瘦素由(2.49±0.60)μg/L下降至(1.26±0.97)μg/L,体质量减轻4.22%,48h和72h体质量分别减轻12.15%和19.70%,血清瘦素分别降至(0.78±0.19)μg/L和(0.62±0.16)μg/L。与正常大鼠相比,禁食24h杏仁基底外侧核瘦素受体表达增强犤LR-IR细胞数(131±8.9)个/mm2,(68±10.4)个/mm2犦,禁食48h瘦素受体表达水平(82±12.6)个/mm2接近正常大鼠,禁食72h瘦素受体阳性细胞明显减少(49.0±7.4)个/mm2。

BACKGROUND:Starvation is a crucial process of fat metabolism, which can trigger adaptive responses.During starvation,leptin concentration falls down,but it is not clear whether the expression of leptin receptor in the brain changes. OBJECTIVE:To investigate the possible changes of leptin receptor expression during starvation and the effects on the basolateral nucleus of amygdala(BLA) and the central nucleus of amygdala(CeA). DESIGN:A randomized controlled trial. SETTING and MATERIALS:The experiment was conducted at the First Hospital of Xi'an Jiaotong University.A total of 20 adult health male Sprague-Dawley(SD) rats were randomly divided into groups of 24-hour fasting,48-hour fasting,72-hour fasting and control group with five rats in each group. INTERVENTIONS:Mass,body length and tail length of all the rats in each group were measured before and after fasting.Leptin concentration was measured by radioimmunoassay(RIA),and the expression of leptin receptor and glial fibrillary acidic protein(GFAP) were measured by ABC immunohistochemical method. MAIN OUTCOME MEASURES:①mass loss,Lee index and the level of serum leptin and blood sugar in rats;②the expression of leptin receptor;③the expression of GFAP. RESULTS:After 24-hour fasting,serum leptin was decreased from (2.49 ±0.60) μg/L to(1.26±0.97) μg/L,and the mass was decreased by 4.22%.After fasting for 48 hours and 72 hours,the mass was decreased by 12.15%and 19.70%respectively,and the level of serum leptin fell to(0.78±0.19) μg/L and(0.62±0.16) μg/L respectively.Compared with the normal rats,24 hours after fasting, the expression of leptin receptor in BLA was increased[LR-IR(131±8.9)/ mm2 ,(68±10.4)/ mm2],and 48 hours after fasting,leptin receptor expression[(82±12.6)/mm2] was close to that of the normal rats;and 72 hours after fasting,the number of positive cells of leptin receptor was markedly decreased(49.0±7.4) /mm2.The expression of leptin receptor in CeA showed no significant difference before and after fasting,and 24 hours and 48 hours after fasting,staining showed that there was no difference found in the number of positive cells in BLA with GFAP compared with the control group. CONCLUSION:During starvation, when the level of serum leptin decreased,the expression of leptin receptor in BLA is up-regulated , so starvation may regulate the sensitivity of BLA to leptin.