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

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5、10min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。

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

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 2...