重组瘦素干预对营养性肥胖大鼠脑组织瘦素受体表达的影响  

Effects of Recombinant Leptin on Expressions of OB-R and OB-Rb mRNA in Brains of Diet-Induced Obese Rats

作　　者：刘倩琦[1] 陈荣华[1] 郭锡熔[1] 郭梅[1] 费莉[1] 

机构地区：[1]南京医科大学第二临床医学院儿科研究所,南京210029

出　　处：《实用儿科临床杂志》2005年第12期1185-1187,I0057,共4页Journal of Applied Clinical Pediatrics

基　　金：国家自然科学基金资助(39870362;30371502);江苏省科委自然科学基金资助(BK99136)

摘　　要：目的观察重组瘦素(leptin)对营养性肥胖大鼠脑组织瘦素特异性受体(OB-R和OB-Rb)mRNA表达的影响,探讨OB-R和OB-Rb表达水平的变化及与肥胖发生的关系,以期更加深入地研究肥胖症发生的中枢信号转导机制。方法雄性大鼠54只随机分成2组,分别喂以普通饲料和高营养饲料共7周;模型制备后再将正常组和肥胖组分别分成3组:正常对照组、正常leptin干预组、正常生理盐水干预组和肥胖对照组、肥胖leptin干预组、肥胖生理盐水干预组,每组各9只。参照Noble法及大鼠脑冠状面定位图谱,给大鼠行右侧脑室插管。恢复7d后,每日10Am在大鼠清醒状态下从导管注入重组leptin5μL(1μg/μL)或等量的生理盐水,连续5d。大鼠处死前,经升主动脉灌注4%多聚甲醛固定,制作石蜡切片、制备地高辛标记的RNA探针,应用原位杂交技术及DIG-AP-NBT-BCIP免疫学检测观察OB-R和OB-RbmRNA的表达水平。结果肥胖leptin干预组大鼠(A=0.336±0.060,t=5.45P<0.01)和正常各组脑组织中大鼠(A分别为0.312±0.072、0.347±0.077和0.341±0.078)OB-RbmRNA的表达水平均较肥胖对照组(A=0.164±0.051,t=4.91P<0.01)、肥胖生理盐水组(A=0.172±0.057)明显增高,而各组间OB-RmRNA的表达未见显著性差异(F=0.334P=0.89)。结论重组leptin干预可增加脑组织中OB-RbmRNA的表达,OB-Rb表达水平的变化可能参与肥胖发生的中枢信号转导机制。Objective To investigate the effects of intracerebroventricular injection of recombinant leptin on expressions of OB R and OB Rb mRNA in the brains of diet induced obese rats, and the mechanism of obesity at the level of central nerve system further. Methods Male SD rats were fed either a standard diet or a high - nutrition diet for 7 weeks. After 7 weeks, rats in normal group （ n 27） and obese group（ n = 27） were randomly divided into 3 groups, respectively, Lateral ventricular cannulation was performed in obese and normal rats received an intracerebroventricular injection of 5μL,（ 1 μg/μL） recombinant leptin and 5 μL saline daily for 5 days. Before scacrifice, the brains were mounted with 4% parafomaaldehyde perfusion and quickly removed. Section in a comical plane at 10 Am was mounted on RNase free slides and treated with 4 % parafomaldehyde. Non - radioactive in sltu hybridization with DIG - labeled OB - R and OB - Rb RNA probe and true - color medical image system were used to examine the expression of OB R and OB - Rb mRNA in brains of rats. Resutls The expresion of OB - Rb mRNA in the brains increased significantly in obese groups with leptin injection and all nomml groups（A 0. 336 ± 0. 060,0.312 ± 0. 072,0. 347 ± 0. 077 mid 0. 341 ±0. 078, respectively） than those of obese group without treatment（A 0. 164 ± 0. 051 ） and with saline trcamtent （A = 0. 172 ± 0,057）. But no difference in the expression of OB - R mRNA was delected among all groups（ F 0. 334 P = 0.89 ）. Conclusions Intracerebmventricular injection of recombinant leptin can increase the expression of OB Rb mRNA, which many play an important role in the pathogenesis of obesity, in diet induced obese rats.

关 键 词：瘦素 受体 注射 脑室内 肥胖症 大鼠 

分 类 号：R589.2[医药卫生—内分泌]