长程高脂饲料对雌雄大鼠胰岛功能损害差异的探讨  

Gender difference of impaired pancreatic function induced by long-term high-fat diet and its underlying mechanism

作　　者：王喆[1] 甘立霞[1] 卢忠燕[1] 何凤田[1] 邹全明[2] 

机构地区：[1]第三军医大学基础医学部生物化学与分子生物学教研室,重庆400038 [2]第三军医大学医学检验系临床微生物学及免疫学教研室,重庆400038

出　　处：《第三军医大学学报》2008年第9期779-782,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金(30570888,30670998);全军医学科研“十一五”计划国际合作项目(06H025)~~

摘　　要：目的动态观察长程高脂饲料对雌雄大鼠糖耐量和胰岛素作用的影响,并探讨其可能的机制。方法取正常SD大鼠100只,抽签式随机分组,其中雄性和雌性大鼠普通饲料组各20只,雄性和雌性大鼠高脂饲料组各30只。每个月动态监测大鼠体质量及空腹血糖的变化,在第14个月时进行腹腔注射糖耐量试验(IPGTT),检测葡萄糖耐量减退(IGT)的情况,测定第14个月时的空腹胰岛素分泌量及大鼠胰腺组织匀浆液中线粒体和微粒体的丙二醛(MDA)、谷胱甘肽(GSH)和过氧化氢酶(catalase,CAT)水平。结果第14个月时无论普食组或高脂组雄性大鼠腹腔注射糖耐量都受损,而雌性大鼠都未达到糖耐量受损,腹腔糖耐量测试表明雌雄大鼠在120min时血糖有显著性差异(P<0.05);14个月时高脂组雄性大鼠空腹胰岛素分泌量显著高于雌性大鼠(P<0.05);胰岛素抵抗指数(HOMA-IR)显示高脂组雄性大鼠胰岛素抵抗程度较雌性大鼠显著升高(P<0.05);早相胰岛素分泌功能显示经过长程高脂喂养,雄性大鼠早相胰岛素分泌功能显著低于雌性大鼠(P<0.05);胰腺组织匀浆液中线粒体的MDA、细胞质的GSH和CAT的水平雌雄大鼠间虽然无显著性差异(P>0.05),但总体趋势是无论是普食组还是高脂组,雄性大鼠氧化应激水平都高于雌性大鼠,抗氧化应激水平都低于雌性大鼠。结论雌性大鼠具有抵抗高脂诱导的糖耐量受损作用,其胰腺组织氧化应激水平较低可能是机制之一。Objective To explore the effect of long-term high-fat diet （HF） on glucose tolerance and insulin action in male and female SD rats and the underlying mechanism. Methods Totally 100 SD rats were equally divided by gender and further subgrouped into standard laboratory chow （SC, n = 20） and HF groups （n = 30）, respectively. Body weight and fasting glucose levels were measured every month, and intraperitoneal glucose tolerance test （IPGTF） was performed in the 5, 8, 10 and 14 months. At the 14th month, fasting plasma insulin concentration was measured, and the contents of malondialdehyde （MDA）, glutathione （ GSH）, and catalase in different fraction of pancreatic homogenates, mitochondria or microsome, were determined. Results Impaired glucose tolerance was observed in both SC and HF male rats hut not in female rats. Fasting insulin levels and homeostasis model assessment of insulin resistance （HOMA-IR） were higher in male rats than in female rats from SC groups and significantly higher in HF feeding rats. Whereas, insulin secretion capacity was significantly lower in male than in female. MDA in pancreatic mitochondria was higher and GSH and catalase in pancreatic cytosol was lower in male than in female. Conclusion Female are relatively protected from induced glucose tolerance under HF feeding and is likely, at least in part, from ameliorated oxidative stress in pancreas.

关 键 词：长程高脂 雌雄大鼠 胰岛功能 氧化应激 

分 类 号：R-33[医药卫生] R151.1