罗格列酮对高脂血症大鼠拮抗胰岛素抵抗及脂肪性肝损伤作用(英文)

Effects of rosiglitazone on antagonizing insulin resistance and adipose liver damnification in hyperlipemic rats

背景:有实验表明在胰岛素缺乏的糖尿病动物应用罗格列酮并未发现明显的增加胰岛素和降血糖作用,说明该药不刺激胰岛素分泌,其改善胰岛素抵抗的作用及对肝、肾脏功能的影响有待研究。目的:观察罗格列酮对高脂血症大鼠胰岛素抵抗是否有改善作用并分析其可能的作用机制。单位:广州市中医医院,广州市中医中药研究所。设计:分层随机对照动物实验。材料:选用64只SD大鼠,鼠龄6-8周,雌雄各半,体质量150-180g,均购自广东省医用实验动物中心;基础饲料:总热量6.9kJ/g(其中蛋白质占23%,碳水化合物占53%,脂肪占5%)。高脂乳液:猪油200g/L,胆固醇200g/L,牛胆盐10g/L,丙二醇200g/L,吐温-80200g/L,总热量15.5kJ/g。高脂肪-高糖-高热量饲料:基础饲料加100g/L葡萄糖、200g/L猪油和100g/L蛋黄粉充分混匀后,制成饼块,烘干后用,总热量21.3kJ/g(其中蛋白质占15%,碳水化合物占51%,脂肪占30%);罗格列酮片:葛兰素史克(天津)有限公司生产(5mg/tab,批号:02110012);格列齐特片:法国施维雅药厂天津华津制药厂合作生产(100mg/tab,批号:00232)。方法:实验于2003-04/07在广州中医药大学完成。①按性别、体质量随机抽取16只大鼠作为空白对照组,喂饲普通饲料,共6周。其余大鼠按照参照文献方法灌服高脂乳液,取空腹血糖≥6.1mmol/L或2h血糖≥7.8mmol/L的大鼠,按体质量和血糖值将大鼠分成3组:模型组、罗格列酮组和格列齐特组,每组16只。空白对照组大鼠不给予处理。罗格列酮组及格列齐特组大鼠分别灌胃给予罗格列酮(5mg/kg)及格列齐特(100mg/kg),模型组灌胃蒸馏水,同时分别继续喂饲高脂饲料,1次/d,共28d,第21天开始同时灌服高脂乳液,1次/d,共7d,末次给药后,禁食18h,第29天采用血糖仪检测各组大鼠空腹血糖,按体质量分别灌胃2.78mol/10mL·kg葡萄糖溶液或葡萄糖-药物混合液10mL/kg,2h后测2h血糖。②全部大鼠眼眶放血并分离血清,分别测定空腹血清血糖、胆固醇、三酰甘油、高密度脂蛋白胆固醇、低密度脂蛋白-胆固醇、丙氨酸氨基转移酶、天冬氨酸氨基转移酶、血清尿素氮、肌酐、肿瘤坏死因子α及胰岛素含量,同时按李光伟方法计算胰岛素敏感指数:胰岛素敏感指数=In[1/(空腹胰岛素浓度×空腹血糖浓度)]。处死大鼠,制肝匀浆,测肝三酰甘油,超氧化物歧化酶,还原型谷胱甘肽和丙二醛水平。主要观察指标:①大鼠空腹血糖及2h血糖检测结果。②大鼠血清大鼠血糖、血脂、肿瘤坏死因子α、胰岛素含量及胰岛素敏感指数检测结果。③大鼠肝细胞三酰甘油含量、还原型谷胱甘肽贮量、超氧化物歧化酶活性及丙二醛含量检测结果。④大鼠血清丙氨酸氨基转移酶,天冬氨酸氨基转移酶,血清尿素氮及肌酐检测结果。结果:①大鼠空腹血糖及2h血糖检测结果:罗格列酮组大鼠空腹血糖及2h血糖分别为(3.2±0.3),(6.3±1.2),mmol/L,低于模型对照组[(3.8±0.5),(8.1±2.1)mmol/L,P<0.01]。格列齐特组大鼠空腹血糖为(3.3±0.7)mmol/L,低于模型对照组。②大鼠血清血糖、血脂、肿瘤坏死因子α、胰岛素含量及胰岛素敏感指数检测结果:罗格列酮组大鼠空腹血糖、肿瘤坏死因子α及空腹胰岛素浓度分别为(4.2±1.2)mmol/L,(246±45)μg/L,(133±45)pmol/L,低于模型对照组[(6.6±1.5)mmol/L,(294±65)μg/L,(264±76)pmol/L,P<0.05-0.01],胰岛素敏感指数高于模型对照组(-6.33±0.46,-7.46±0.95,P<0.01)。格列齐特组大鼠空腹血糖及肿瘤坏死因子α浓度分别为(4.1±1.1)mmol/L,(251±62)μg/L,低于模型对照组(P<0.05-0.01)。③大鼠肝细胞三酰甘油含量、还原型谷胱甘肽贮量、超氧化物歧化酶活性及丙二醛含量检测结果:罗格列酮组大鼠肝细胞三酰甘油、丙二醛含量分别为(1.00±0.38),(40±17)mmol/g,低于模型对照组[(2.40±0.60),(171±63)mmol/g,P<0.01],还原型谷胱甘肽贮量、超氧化物歧化酶活性分别为(51±14)mg/g,(583.45±50.01)nkat/g,高于模型对照组[(2.40±0.60)mg/g,(450.09±66.68)nkat/g,P<0.05-0.01]。格列齐特组大鼠肝细胞三酰甘油、丙二醛含量分别为(1.20±0.38),(100±30)mmol/g,低于模型对照组,还原型谷胱甘肽贮量(46±15)mg/g,高于模型对照组。④大鼠血清丙氨酸氨基转移酶,天冬氨酸氨基转移酶,血清尿素氮及肌酐检测结果:罗格列酮组大鼠血清尿素氮,肌酐含量分别为(14.3±3.8)mmol/L,(33±9)μmol/L,低于模型对照组[(19.2±5.6)mmol/L,(45±13)μmol/L,P<0.05]。结论:罗格列酮和格列齐特均能改善高脂饲养引发的胰岛素抵抗,罗格列酮在降低高脂病鼠高胰岛水平、降低血清尿素氮及肌酐含量、提高还原型谷胱甘肽贮量作用和增强超氧化物歧化酶活性的趋势方面优于格列齐特。

BACKGROUND： Some experiments indicated that applying rosiglitazone on diabetic animals lacking of insulin could not increase insulin and lower blood glucose obviously, which showed that rosiglitazone did not stimulate the excretion of rosiglitazone. The action of rosiglitazone in improving insulin resistance and the effects on the functions of liver and kidneys need more investigations. OBJECTIVE： To investigate whether rosiglitazone can improve the insulin resistance of rats with hypedipemia, and analyze the possible mechanism. SETTINGS： Guangzhou Hospital of Traditional Chinese Medicine; Guangzhou Institute of Traditional Chinese Medicine and Materia. Medica DESIGN ： A stratified randomized controlled animal trial. MATERIALS ： Sixty-four Sprague-Dawley （SD） rats （Batch No. 2002A024）, SPF grade, half male and half female, weighing 150 to 180 g, aged 6 to 8 weeks were purchased from Guangdong Medical Experimental Animal Center. Normal feed （total quantity of heat 6.9 kJ/g） was enriched with 23% protein, 53% carbohydrate and 5% fat. High fat emulsion （total quantity of heat 15.5 kJ/g） was enriched with 200 g/L lard, 200 g/L cholesterol, 10 g/L bile salt ox, 200 g/L propylene glycol, 200 g/L tween-80. High fat and sugar feed （total quantity of heat 21.0 kJ/g） was enriched with 15% protein, 51% carbohydrate and 30% fat after adding 100 g/L glucose, 200 g/L lard and 100 g/L yolk powder then mixing and baking. Rosiglitazone was from GlaxoSmithKline Co Ltd. （Tianjin） （5 mg/tab, Batch No.02110012）. Gliclazide was from Servier International and Tianjin Hua Jin Pharmaceutical Factory （100 mg/tab, Batch No.00232）. METHODS ： The experiment was carried out in Guangzhou University of Traditional Chinese Medicine from April to July in 2003. （1） Sixty-four Sprague-Dawley rats, 16 of which were randomly sampled as the normal control group and had been fed with normal feed for 6 weeks. The others were modeled after medical literatures, each one was administered with high fat emulsion （10 mL/kg） by gavage once a day for 14 days. Rats whose FBG ≥6.1 mmol/L or 2hBG ≥7.8 mmol/L were selected, randomized into 3 groups according to body mass and blood glucose, i.e., negative control （model） group, rosiglitazone group and gliclazide group, there were 16 rats in each group. Except the normal control group, rats in the rosiglitazone group and gliclazide group were gavaged with rosiglitazone for 5 mg/kg and gliclazide for 100 mg/kg respectively, and those in the model group were gavaged with distilled water. All of the rats were fed with high-fat feed once a day for 28 days. From the 21^st day, high fat emulsion was added Once a day for 7 days. After fasting for 18 hours from the last administration, all the rats were recorded for FBG and administered dextrose 2.78 mol/10 mL·kg or dextrose and drug mixture 10 mL/kg by body mass. Two hours＇ later, 2hBG was recorded. （2） Blood samples were collected from orbital plexus and serum was prepared for detecting the biochemical indexes and immunological indexes in serum, i.e., fasting serum glucose（FSG）, total cholesterol （TC）, triglyceride （TG）, high density lipoprotein cholesterol （HDL-C）, low density lipoprotein cholesterol （LDL-C）, alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, blood urea nitrogen （BUN）, creatinine （Cr）, tumor necrosis factor alpha （TNF-cx） and fasting insulin （FINS）. The insulin sensitivity index （ISI） was calculated： ISl=ln [1/ （FINS contentxFBG content）]. After the rats were killed, their liver suspension was prepared for measuring the levels of TG, superoxide dismutase （SOD）, glutathione （GSH） and malondialdehyde （MDA）. MAIN OUTCOME MEASURES ： （1） FBG and 2hBG; （2） FSG, blood lipids, TNF-α, FINS and ISI in serum; （3） TG, GSH, SOD and MDA in liver cells; （4） ALT, AST, BUN and Cr in serum. RESULTS： （1） Results of FBG and 2hBG： The FBG and 2hBG in the rosiglitazone group [（3.2±0.3）, （6.3±1.2） mmol/L] were lower than those in the model.control group [（3.8±0.5）, （8.1±2.1） mmol/L, P 〈 0.01]. The FBG in the gliclazide group [（3.3±0.7） mmol/L] was lower than that in the model control group. （2） Results of FSG, blood lipids, TNF-α, FINS and ISI： The FSG, TNF-α and FINS in the rosiglitazone group were （4.2±1.2） mmol/L, （246±45） μg/L and （133±45） pmol/L respectively, which were lower than those in the model control group [（6.6±1.5） mmol/L, （294±65） μg/L, （264±76） pmol/L, P 〈 0.05-0.01], whereas ISI was higher than that in the model control group （-6.33±0.46, -7.46±0.95, P 〈 0.01）. The FSG and TNF-α in the gliclazide group [（4.1±1.1） mmol/L, （251±62） μg/L] were lower than those in the model control group （P 〈 0.05-0.01）. （3） Results of TG content, GSH deposit, SOD activity and MDA content in liver cells： The TG and MDA contents in liver cells in the rosiglitazone group [（1.00±0.38）, （40±17） mmol/g] were lower than those in the model control group [（2.40±0.60）, （171±63） mmol/g, P 〈 0.01], the GSH deposit and SOD activity [（51±14） mg/g, （583.45± 50.01 ） nkat/g] were higher than those in the model control group [（2.40±0.60） mg/g, （450.09±66. 68） nkat/g, P 〈 0.05-0.01]. The TG and MDA contents in the gliclazide group [（1.20±0.38）, （100±30） mmol/g] were lower than those in the model control group, whereas the GSH deposit [（46±15） mg/g] was higher than that in the model control group. （4） Results of ALT, AST, BUN and Cr in serum： The serum contents of BUN and Cr in the rosiglitazone group [（14.3±3.8） mmol/L, （33±9） μmol/L] were lower than those in the model control group [（19.2±5.6） mmol/L, （45±13）μmol/L, P 〈 0.05]. CONCLUSION： Both rosiglitazone and gliclazide can improve the insulin resistance induced by high fat feed. Rosiglitazone is superior to gliclazide in decreasing the high insulin level, decreaseing serum levels of BUN and Cr, improving reduced GSH deposit and enhancing SOD activity.