摘要
目的 :探讨高脂饮食诱导下肥胖易感 (OP)大鼠肥胖抗性 (OR)大鼠在体重、食量、Lee′s指数、脂肪湿重、血脂及脂肪组织脂蛋白脂酶 (LPL)基因表达等方面的生理学差异。方法 :4 8只SD大鼠 ,以高脂饲料饲养 1周后 ,按体重增值从大到小百分排序 ,取第 75百分位以上为OP组 ,第 2 5百分位以下为OR组 ,继续高脂饲养 4周 ;观察各大鼠体重变化、摄食量、Lee′s指数、脂肪湿重、血脂等 ,采用NorthernBlot分析脂肪组织中LPL基因的mRNA表达水平。结果 :①OP大鼠的体重增值、热能摄入、Lee′s指数及腹腔脂肪湿重均显著高于OR大鼠 ,但血脂水平两组间无差异 ;②高脂饲养 1周、5周时OP大鼠体重增值分别是OR大鼠的 6 .5 4、4 .2 5倍 ,热能摄入仅为OR大鼠的 1.13、1.15倍 ;③OP大鼠脂肪组织中LPL基因的mRNA表达水平显著高于OR大鼠。结论 :OP与OR大鼠间存在生理学差异 ,其原因除OP大鼠热能摄入较多因素外 ,OP大鼠体内较高的能量效能是其肥胖易感性较高的重要因素 ,而能量效能与脂肪组织LPL基因的表达水平可能存在密切关系。
Objective: To observe the differences of partial physiologic indexes including weight, food intake, Lee's index, the wet weight of fat pad, plasma lipids and the genetic expression of LPL mRNA in adipose tissue between obesity-prone rats (OP) and obesity-resistant rats (OR) on a high-fat diet. Methods: After 1 week of free access to a high-fat diet (HFD), 48 rats were separated on the basis of 1 week body weight percentage gained in OP (OP≥P75) or OR (OR≤P25) groups. Rats were continuously fed on the HFD for another 4 weeks. The body weight and food intake were recorded in the course of model-making. And the Lee's index, the plasma lipid and lipoproteins, the wet weight of both epididymal and retroperitoneal fat pad were measured after the rat was killed. And the level of LPL mRNA expression in adipose tissue was detected by Northern Blot technique. Results: ① In OP rats, the speed of body weight gain, the cumulative energy intake, the Lee's index, and the wet weight of fat pad at both epididymal and retroperitoneal sites were significantly higher than those in OR rats, but there was no significant difference in the level of plasma lipid and lipoproteins between these two groups. ② After 1 week and 5 weeks on the high-fat diet, the gain of body weight in OP rats were about 6.45 and 4.25 times of those in OR rats. Meanwhile, the cumulative energy intake in OP rats was only about 1.13 and 1.15 times of those in OR rats. ③ Despite the depressive effect of the high-fat diet on the level of LPL mRNA expression in adipose tissue, there was a significant level of LPL mRNA in adipose tissue of OP rats compared with that in OR rats. Conclusion: The physiologic differences exist between OP and OR rats. Besides a higher level of energy intake, the higher energy efficiency associated with LPL mRNA expression in adipose tissue may also contribute to the enhancement of susceptibility to obesity in OP rats.
基金
DepartmertofPediatries,theSecondHospitalofLianyungang ,Lianyungang 2 2 2 0 2 3 ,P .R .China
