摘要
目的观察长期等热量高蛋白饮食对营养性肥胖大鼠胰岛形态功能的影响。方法利用高脂饲料建立营养性肥胖大鼠模型34只,分为高蛋白饲养组(HP组,n=12)、高脂饲养组(HF组,n=11)、普通饲养组(NC组,n=11),正常等热量饲养24周后,观察体质量、内脏脂肪及空腹血浆GLP-1的改变,行静脉葡萄糖耐量试验(IVGTT)观察胰岛分泌功能,作胰岛素免疫组化染色进行胰岛形态学分析。结果与NC组相比,HP组体质量、内脏脂肪均显著降低[分别为(490.92±39.47)gvs(545.55±31.08)g,P<0.01,(22.42±7.04)gvs(32.33±9.27)g,P<0.05],HF组则均明显增加[分别为(656.01±58.49)gvs(545.55±31.08)g,(55.33±17.81)gvs(32.33±9.27)g,P均<0.01]。IVGTT结果显示,各点血糖无差异,但HP组5、10min血清胰岛素显著降低[(91.56±21.72)mIU/Lvs(121.29±34.03)mIU/L,;(58.62±15.80)mIU/Lvs(81.12±24.36)mIU/L,P均<0.05];而HF组0、10min显著升高[(40.21±14/12)mIU/Lvs(27.48±11.31)mIU/L,(98.15±27.58)mIU/Lvs(81.12±24.36)mIU/L,P均<0.05]。空腹血浆GLP-1水平HP组显著降低[(0.52±0.13)μg/Lvs(0.71±0.19)μg/L,P<0.05],HF组则有增加趋势[(1.03±0.28)μg/Lvs(0.71±0.19)μg/L,P=0.11]。免疫组化结果显示,与NC组相比,HP组胰岛形态无改变,但HF组已出现胰岛显著增大、胰岛染色面积比率明显降低及平均灰度升高(P<0.05)。结论高脂饮食可造成胰岛形态功能受损,而长期等热量高蛋白饮食虽能降低营养性肥胖大鼠胰岛素的第一时相分泌,但尚未引起胰岛形态变化。该组胰岛素分泌减少可能与空腹GLP-1降低、体质量减轻有关。
Objective To investigate the effects of a long-term isocaloric high-protein diet on morphology and function of the pancreatic islet in diet-induced obese rats.Methods：Diet-induced obese rat models were established by feeding a fat-enriched diet.The obese male rats were randomly divided into three groups：the high-protein diet group（HP group,n=12）,the high-fat diet group（HF group,n=11）,and the normal food group（NC group,n=11）.The total calorie ingestion of each rat per day was similar and was maintained for 24 weeks.Then body weight,visceral fat mass and fasting plasma glucagon-like peptide-1（GLP-1）were determined.The insulin secretory function of the islet was evaluated by an intravenous glucose tolerance test（IVGTT）,and morphological analysis of the pancreatic islet was assessed by immunohistochemistry.Results Compared with the NC group,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,but those indices were both higher [（656.01±58.49）g vs（545.55±31.08）g,（55.33±17.81）g vs（32.33±9.27）g,and both P〈0.01] in the HF group.As to IVGTT,there were no differences in blood glucose among the three groups,but the serum insulin levels at 5min and 10 min were significantly lower in HP than in NC [（91.56±21.72）mIU/L vs（121.29±34.03）mIU/L;（58.62±15.80）mIU/L vs（81.12±24.36）mIU/L,both P〈0.05],and 0 min and 10 min insulin levels were significantly higher in HF than in NC[（40.21±14.12）mIU/L vs（27.48±11.31）mIU/L,（98.15±27.58）mIU/L vs（81.12±24.36）mIU/L,both P〈0.05].Plasma GLP-1 level was significantly lower in HP rats [（0.52±0.13）μg/L vs（0.71±0.19）μg/L,P〈0.05],and there was an increased trend in the HF group [（1.03±0.28）μg/L vs（0.71±0.19）μg/L,P=0.11] compared with the NC group.Immunohistochemistry showed that there were no differences in morphology between HP and NC rats,but HF rats had a larger i
出处
《山东大学学报（医学版）》
CAS
北大核心
2009年第10期1-4,14,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)
