长期高蛋白饮食对营养性肥胖大鼠胰岛素分泌和血浆Ghrelin水平的影响  

Effects of long-term high-protein diet on insulin secretion and plasma Ghrelin in diet-induced obese rats

作　　者：马立川[1] 李明龙[1] 陈海燕[1] 赵树娥[1] 林爱清[1] 蔺新英[2] 

机构地区：[1]山东大学附属省立医院保健内分泌科,济南250021 [2]山东大学公共卫生学院营养与食品卫生学研究所,济南250012

出　　处：《山东大学学报（医学版）》2009年第5期23-26,30,共5页Journal of Shandong University:Health Sciences

基　　金：山东省自然科学基金重点项目(Z2006C09)

摘　　要：目的观察长期高蛋白饮食对营养性肥胖大鼠胰岛素分泌和血浆Ghrelin水平的影响。方法采用高脂饲料喂养,建立营养性肥胖大鼠模型。将肥胖大鼠分为高蛋白饲料组(HP组,n=12,36.7%蛋白质)和普通饲料组(NC组,n=11,22.4%蛋白质),正常等热量饲养24周。观察饲养期间大鼠体质量、空腹血糖的变化。至24周,测定内脏脂肪、空腹血浆Ghrelin(酶联免疫法)和空腹胰岛素(放射免疫法)等指标含量,并行静脉葡萄糖耐量试验(IVGTT),观察两组大鼠葡萄糖刺激下的胰岛素分泌状况。结果与NC组相比,HP组体质量明显减轻[(490.92±39.47)g vs(545.55±31.08)g,P<0.01],内脏脂肪含量明显减少[(22.42±7.04)g vs(32.33±9.27)g,P<0.05];IVGTT结果显示,HP组51、0 min血清胰岛素含量显著降低[(91.56±21.72)μIU/mL vs(121.29±34.03)μIU/mL,P<0.05;(58.62±15.80)μIU/mL vs(81.12±24.36)μIU/mL,P<0.05];HP组空腹血浆Ghrelin浓度有升高趋势[(2.36±0.82)ng/mL vs(1.95±0.64)ng/mL,P=0.20]。血浆Ghrelin浓度与体质量(r=-0.373,P<0.05)、内脏脂肪含量(r=-0.454,P<0.01)、空腹胰岛素含量(r=-0.390,P<0.05)呈负相关。结论长期等热量高蛋白饮食可降低肥胖大鼠胰岛素的第一时相分泌,并可导致空腹Ghrelin升高。这种胰岛素分泌的减少可能系Ghrelin升高、体质量减轻所致。Objective To investigate the effects of long-term isocaloric high-protein diet intake on insulin secretion and plasma Ghrelin in diet-induced obese rats. Methods Diet-induced obese rat models were established by feeding with a high fat food. The obese male rats were randomly divided to two groups： the high-protein diet group （ HP, 36.7 % of energy from protein, n = 12） and the regular diet group （NC, 22.4% of energy from protein, n = 11）. The total calorie ingestion of each rat per day was similar and was maintained for 24 weeks. Body weight and fasting blood glucose were determined during the feeding period. After 24 weeks, visceral fat mass, fasting plasma Ghrelin （by enzyme-immunoassay, EIA） and fasting insulin （by radio-immunoassay, RIA） were assayed. To evaluate the insulin secretive function of β cells, serum levels of insulin were determined in an intravenous glucose tolerance test （IVGTT）. Results Body weight [ （ 490.92 ± 39.47） g vs （545.55± 31.08） g, P 〈 0.01 ] and visceral fat mass [（22.42±7.04）g vs （32.33±9.27）g, P〈0.05] in HP rats were significantly lower than those in NC rats. The serum insulin levels in 5 and 10 min of IVGTr were significantly lower in HP than in NC [ （91.56 ± 21.72） μIU/mL vs （121.29±34.03）μlU/mL, P〈0.05; （58.62±15.80）μlU/mLvs（81.12±24.36）μlU/mL, P〈0.05]. HP rats had anincreased trend in plasma Ghrelin level [ （2.36 ±0.82） ng/mL vs （ 1.95 ±0.64） ng/mL, P = 0.20]. Plasma Ghrelin was nega- tively correlated with body weight （ r = - 0.373, P 〈 0.05）, visceral fat mass （ r = - 0. 454, P 〈 0.01 ） and fasting insulin （ r = -0.390, P 〈0.05）. Conclusion Long-term isocaloric high-protein ingestion may reduce the first phase secretion of insulin and increase fasting plasma Ghrelin level in diet-induced obese rats. The decrease of insulin secretion may be secondary to CAn^lin increment and weight loss.

关 键 词：模型 动物 营养性肥胖 蛋白质 胰岛素 GHRELIN 大鼠 WISTAR 

分 类 号：R587[医药卫生—内分泌] R-332[医药卫生—内科学]