目的:比较不同方式高脂饮食对大鼠脂肪组织黑色素聚集激素受体1(melanin concentrating hormon ereceptor1,MCHRl)和瘦素受体(OB—Rb)表达的影响。方法:断乳大鼠分成3组:正常膳食组(NC组,13%热卡来自脂肪),与正常膳食组等热量的高脂膳食组(PHF组,47%热卡来自脂肪)及自由摄入高脂膳食组(HF组,47%热卡来自脂肪)。喂养8周后,称量大鼠体质量,检测血清中的黑色素聚集激素(melanin concentrating hormone,MCH)和瘦素(1eptin)浓度。运用实时定量PCR检测脂肪组织的MCHRl和OB-Rb mRNA水平。结果:HF组和PHF组体质量显著高于NC组(P〈0.01),血清中MCH和leptin浓度较NC组有明显增高(MCH,P〈0.01;leptin,P〈0.05)。同对照组相比,HF组和PHF组脂肪组织中的MCHRlmRNA水平显著升高(P〈0.05),而OB-RbmRNA却显著降低(HF组,P〈0.01;PHF组,P〈0.05)。HF组和PHF组的体质量、血清学指标及实时定量PCR结果差异无统计学意义(P〉0.05)。结论:等热量和高热量高脂膳食都能诱导大鼠肥胖和代谢异常;高脂膳食所诱导的机体肥胖及代谢紊乱与脂肪组织中MCHRlmRNA上调和OB-RbmRNA下调有关。
Objective To investigate the effect of high-fat (HF) diet on the body weight and the mRNA expression of melanin concentrating hormone receptor 1 (MCHR1) and leptin receptor (OB-Rb) in the adipose tissue in rats, the two important and opposite factors in regulating the body weight. Methods Post-weaning rats were divided into 3 groups: the NC group were fed a normal- chow diet (NC) (13% calories from fat), the HF group with a HF-diet (47% calories from fat) and the PHF group pair-fed a HF-diet (47% calories from fat). At the end of 8th week, the gained bodyweight, the plasma melanin concentrating hormone (MCH) and leptin, and the expression levels of MCHR1 and OB-Rb in the adipose tissue were measured. Results Both the HF-diet and pair-fed HF-diet enhanced the body weight (P 〈 0.01 ), plasma MCH (P 〈 0.01 ) and leptin concentrations (P 〈 O. 05). In the adipose tissue, HF-diet resulted in significant increase in MCHR1 (PHF group,P 〈 O. 05 ) and decrease in OB-Rb mRNA levels (HF group, P 〈 O. 01; PHF group, P 〈 O. 05). No statistical difference was found between the HF group and the PHF group in terms of the aforementioned data (P 〉 O. 05 ). Conclusion Chronic intake of iso-caloric HF-diet and ad libitum HF-diet obviously results in increase in the body weight, serum leptin, and MCH concentra- tion. Diet-induced obesity and related metabolic disorders are possibly correlated with up-regulated expression of MCHR1 and down-regulated expression of OB-Rb in the adipose tissue.