银杏叶提取物对实验性2型糖尿病大鼠肝脏的保护作用

目的： 研究银杏叶提取物(EGB)对实验性2型糖尿病大鼠肝脏损伤的影响及机制。方法: 雄性SD大鼠39只，随机分为4组: 正常对照组、高脂组、糖尿病对照组和EGB治疗组。采用高脂饮食加链脲佐菌素（STZ） 诱导2型糖尿病大鼠模型， EGB治疗组给予EGB 8 mg·kg^-1·d^-1治疗8周。用光镜和透射电镜观察EGB对2型糖尿病大鼠肝组织的形态学改变，并检测肝组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GSH-PX)和总一氧化氮合酶(NOS)、诱导型一氧化氮合酶(iNOS)的活性及MDA、NO含量。结果: 糖尿病组光镜下主要表现为肝细胞脂肪变性明显，出现大量脂肪空泡，胞浆内糖原颗粒减少或消失。电镜下主要表现为肝细胞核固缩，胞浆内含大量脂滴，细胞器明显减少，贮脂细胞明显增生，胶原纤维增生。肝组织内GSH-PX、SOD、CAT活性明显低于正常对照组，MDA、 NO含量及总NOS、iNOS 活性显著高于正常对照组； EGB治疗组肝脏组织病理改变较轻，GSH—PX、SOD、CAT 活性明显高于糖尿病组，MDA、NO含量及总NOS、iNOS 活性显著低于糖尿病组。结论: EGB对2型糖尿病大鼠的肝脏具有保护作用、抗脂质过氧化作用和抑制NO的过多产生可能在其中起重要作用。     

香菇多糖对糖尿病大鼠心肌损伤影响的实验研究

目的:研究香菇多糖(LNT)对糖尿病大鼠心肌的保护作用。方法:用光镜和透射电镜观察LNT对链脲佐菌素诱导的糖尿病大鼠心肌的形态学改变, 并测定心肌组织内超氧化物歧化酶(SOD)、一氧化氮合酶(NOS)的活性及一氧化氮(NO)、丙二醛(MDA)的含量。结果:光镜下主要表现为心肌细胞空泡变性及心肌纤维局灶性溶解, 心肌间质纤维增生;电镜下主要表现为心肌线粒体扩张, 嵴变短, 肌原纤维溶解, 间质胶原纤维增生, SOD活性下降, NOS活性及MDA、NO含量增高。LNT治疗组心肌纤维损伤及间质纤维增生明显减轻, 心肌组织内SOD活性LNT治疗组明显高于糖尿病组, NOS活性及MDA、NO含量LNT治疗组低于糖尿病组。结论:LNT可能通过抗脂质过氧化作用和降低NO水平而对糖尿病心肌产生保护作用。     

糖尿病大鼠脑组织学及脂质过氧化和一氧化氮水平的变化

目的:研究糖尿病大鼠脑组织学及脂质过氧化和一氧化氮的变化。方法:用光镜及透射电镜观察四氧嘧啶诱导的糖尿病1个月大鼠脑组织学改变,并测定脑组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、一氧化氮合酶(NOS)的活性及丙二醛(MDA)、一氧化氮(NO)的含量。结果:光镜下可见脑水肿、脑软化、白质脱髓鞘,透射电镜下见到神经元及神经胶质细胞内线粒体肿胀、嵴变短、神经纤维脱髓鞘,血脑屏障受损;SOD、GSH-PX活性下降,NOS活性、MDA、NO含量增加。结论:糖尿病可引起明显的脑组织形态学改变,其中以线粒体最为严重。     

糖尿病大鼠睾丸病理变化及脂质过氧化和一氧化氮的改变

目的:研究糖尿病睾丸的病理变化及其发生机制。方法:用光镜及透射电镜观察四氧嘧啶诱导的糖尿病1个月大鼠睾丸的形态学改变,并测定睾丸组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、一氧化氮合酶(NOS)的活性及一氧化氮(NO)、丙二醛(MDA)含量。结果:光镜下主要表现为睾丸曲细精管萎缩及生精阻滞;透射电镜下主要见到支持细胞线粒体与内质网扩张、胞浆内内含物形成;睾丸组织的SOD、GSH-PX活性实验组低于对照组,NOS活性及NO、MDA含量实验组高于对照组。结论:糖尿病大鼠睾丸病变主要为支持细胞受损及生精障碍,其可能与脂质过氧化作用及NO所致的损伤有关。     

Efficacy of melatonin as protectant against oxidative stress and structural changes in liver tissue in pinealectomized rats

Previous observations demonstrated that physiological levels of melatonin, the pineal secretory product, are important in protecting against oxidative stress-induced tissue damage. We investigated the effects of pinealectomy and administration of exogenous melatonin on liver tissue in rats. Pinealectomized (Px) and sham-operated (non-Px) rats were used. We evaluated structural changes, reduced glutathione (GSH) levels and malondialdehyde (MDA) levels. Rats were divided into three groups (10 rats in each group): control (non-Px), Px+vehicle and Px+melatonin (4 mg/kg given daily intraperitoneally for 10 days). Liver GSH levels were significantly lower in Px rats than in the control group. Melatonin administration significantly increased GSH levels (p < 0.05). Px caused a significant increase in MDA levels as compared with the control group and melatonin administration to Px rats significantly reduced MDA levels in the liver (p < 0.05). Sinusoidal dilatation to a varying degree developed in all Px rats. Severity of mononuclear cell infiltration and sinusoidal congestion were lower in Px+melatonin group than in the Px group. These findings suggest that a significant increase in oxidative and structural changes occur in rat livers after pinealectomy, which can be diminished by melatonin treatment.     

The protective effects of carnosine and melatonin in ischemia-reperfusion injury in the rat liver

The reperfusion following liver ischemia results in hepatocyte damage and apoptosis. The aim of this study was to investigate the effects of two antioxidant agents, carnosine and melatonin, in rat liver ischemia-reperfusion injury. Five study groups were formed; I. sham, II. ischemia-reperfusion, III. ischemia-reperfusion+melatonin, IV. ischemia-reperfusion+carnosine, V. ischemia-reperfusion+melatonin+carnosine. Then 250 mg/kg carnosine and 10 mg/kg melatonin were administered intraperitoneally 30 min before ischemia and immediately after the reperfusion. Sinusoidal dilatation, congestion and neutrophil infiltration were observed in the ischemia-reperfusion group while these symptoms were less pronounced in the treatment groups. Alanine aminotransferase, aspartate aminotransferase and myeloperoxidase levels were increased in the ischemia-reperfusion group while they were lowered in the treatment groups. Glutathione level was low in the ischemia-reperfusion group while it tended to increase in the ischemia-reperfusion+carnosine administered and ischemia-reperfusion+carnosine+melatonin administered groups. There was an increase in the number of apoptotic cells in the ischemia-reperfusion group while this number was lowered in the treatment groups. Carnosine was more effective than melatonin in the reversal of structural and biochemical alterations that resulted from ischemia-reperfusion injury. The administration of melatonin and carnosine together yielded better outcomes compared to the sole administration of each agent.     

Effects of treadmill running on spatial learning and memory in streptozotocin-induced diabetic rats

Previous studies have shown an association between diabetes mellitus and impairments in learning and memory. These deficits were partially reversed by the use of insulin. Due to the fact that exercise has positive effects on many physiological systems, including the central nervous system, the present study, evaluated the effects of treadmill running on spatial learning and memory in streptozotocin (STZ)-induced diabetic rats. The exercise program was treadmill running at 17 meters per minute (m/min) at 0° inclination for 40 minutes per day (min/day), 7 days/week, for 12 weeks. Experimental groups were: the control-rest, the control-exercise, the diabetes-rest and the diabetes-exercise. Spatial learning and memory was investigated by Morris water maze test in the rats after 12 weeks of diabetes induction and the exercise period. Our data showed that spatial learning and memory was significantly impaired in the diabetes-rest group with respect to the control-rest group. However, there were no differences between the other groups. The present results suggest that spatial learning and memory is affected under diabetic conditions and that treadmill running prevents these effects. The data correspond to the possibility that treadmill running is helpful in the prevention and alleviation of the cognitive decline in diabetes mellitus.     

银杏叶提取物对糖尿病大鼠睾丸损伤的作用

目的:研究银杏叶提取物(GBE)对糖尿病所致的睾丸损伤的作用及其机制。方法:用光镜及透射电镜观察链脲佐菌素(STZ)诱导的糖尿病1个月大鼠睾丸的形态学改变,并测定睾丸组织丙二醛(MDA)、NO产物NO₂^-/NO₃^-的含量及超氧化物歧化酶(SOD)、一氧化氮合酶(NOS)的活性。 结果:①糖尿病大鼠睾丸组织光镜下主要表现为睾丸曲细精管萎缩、变形及生精上皮脱落,透射电镜下主要见到支持细胞浆内内质网扩张、脂滴空泡形成,溶酶体明显减少,银杏叶组大鼠睾丸组织光镜、透射电镜下上述病变明显改善。②睾丸组织的MDA、NO₂^-/NO₃^-含量及tNOS和iNOS活性银杏叶组低于糖尿病组,SOD活性银杏叶组高于糖尿病组。 结论:GBE对糖尿病所致的睾丸损伤有明显的保护作用,其作用机制与提高SOD活力减少MDA产生,抑制iNOS活力减少NO产生有密切关系。     

异烟肼灌胃建立小鼠急性肝损伤模型的研究

 目的 探索应用异烟肼灌胃建立小鼠急性肝损伤模型，并初步阐明其机制。 方法 昆明种小鼠 50 只，随机分为异烟肼正常剂量造模组（常量组）、2 倍剂量造模组（2 倍量组）、5 倍剂量造模组（5 倍量组）、8 倍剂量造模组（8 倍量组）和空白对照组，每组各 10 只。各造模组分别以 90、180、450、720 mg/kg 剂量的异烟肼灌胃，18 h 后检测血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）水平并取肝组织进行光镜观察，探索导致明显急性肝损伤的相对合适剂量。另取昆明种小鼠 90 只，随机分为单纯造模组（40 只）、干预造模组（40 只）和空白对照组（10 只），各造模组以相对合适剂量异烟肼灌胃，其中干预造模组于造模前以甘利欣75 mg/kg 体重连续灌胃 5 d，18、36、54、72 h 后分别检测血清 ALT、超氧化物歧化酶（SOD）、丙二醛（MDA）、谷胱甘肽过氧物酶（GSH-Px）水平，并进行肝组织光镜和电镜观察，探索导致明显急性肝损伤的相对合适时间及可能机制。 结果 在探索相对合适剂量实验中，2 倍量组小鼠血清ALT、AST 分别为（101.6 ± 6.3）和（108.1 ± 14.9）U/L，明显高于空白对照组的（30.1 ± 3.6）、（35.3 ± 6.5）U/L 和常量组的（52.8 ± 5.3）、（53.9 ± 8.9）U/L，差异均有统计学意义（均P < 0.05），肝细胞出现广泛的脂肪变性和水肿，肝窦几乎消失；5 倍量组小鼠死亡 7 只，8 倍量组小鼠则全部死亡。在探索相对合适时间及发生机制实验中，应用2 倍剂量异烟肼灌胃后 18 h，单纯造模组小鼠血清 ALT、MDA 水平明显高于空白对照组，SOD、GSH-Px 水平明显低于空白对照组，肝细胞广泛损伤，细胞超微结构显著变化。 结论 应用 2 倍剂量（180 mg/kg）异烟肼灌胃可成功建立小鼠急性肝损伤模型。异烟肼所致急性肝损伤可能与自由基脂质过氧化反应密切相关。     

水飞蓟宾对非酒精性脂肪性肝病线粒体膜流动性的影响

目的:探讨非酒精性脂肪性肝病(NAFLD)大鼠模型中肝脏线粒体膜流动性的改变以及观察水飞蓟宾对NAFLD的防治作用。方法:采用高脂饮食建立非酒精性脂肪性肝病大鼠模型,观察大鼠甘油三酸酯(TG)、胆固醇(TC)、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、丙二醛(MDA)、超氧化物歧化酶(SOD)、肝组织HE染色、脂肪细胞染色的变化,以及肝脏线粒体膜的流动性的改变,并以水飞蓟宾抗氧化治疗,与已知有疗效的罗格列酮对比,观察其对上述指标的影响。结果:模型组血清ALT、AST、TG、TC显著升高,与空白对照组比较差异显著(P0.01)。HE染色提示肝组织呈弥散性脂质蓄积,模型组大鼠肝细胞线粒体微粘度明显高于空白对照组(P0.01)。罗格列酮治疗组TG、AST均得到明显改善(P0.05或P0.01);TC、ALT与模型组比较差异无显著(P0.05)。水飞蓟宾治疗后,TC、TG、ALT以及AST均得到明显改善(均P0.01)。两治疗组大鼠肝MDA含量、肝细胞线粒体微粘度均较模型对照组下降(P0.01),且水飞蓟宾的效果比罗格列酮显著,差异显著(P0.05)。结论:高脂饮食可诱导大鼠NAFLD发生,水飞蓟宾可以有效地防治NAFLD。稳定并维持适当的肝脏线粒体膜流动性、减轻肝脏脂质过氧化可能是水飞蓟宾肝脏保护功能的作用途径。     

Effects of moderate and severe intermittent hypoxia on vascular endothelial function and haemodynamic control in sedentary men

Acclimatization to intermittent hypoxia (IH) improves exercise performance by enhancing oxygen delivery and utilization, but the effect of IH on hemodynamic control remains unclear. This study investigates how two intensities of IH influence hemodynamic control to develop an IH regimen that improves aerobic fitness and minimizes risk of peripheral vascular disorder. Thirty healthy sedentary men were randomly divided into severe (SIH) and moderate (MIH) IH and control (C) groups. The subjects were exposed to 12% (SIH), 15% (MIH), or 21% (C) O₂ for 1 h/day, 5 days/week for 4 weeks in a normobaric hypoxia chamber. The results demonstrate that (1) improved pulmonary ventilation and oxygen uptake by SIH and MIH; (2) SIH elevated blood pressure during exercise and increased plasma malondialdehyde and nitric oxide (NO) metabolite levels, accompanied by reduced hyperaemic arterial response, venous compliance, endothelium-dependent vasodilatation, and decreased plasma total antioxidant and vitamin E levels; (3) while such effects were not seen following MIH; and (4) there were no significant differences in endothelium-independent vasodilatation during all experimental periods among the three groups. We conclude that both SIH and MIH regimens improve pulmonary ventilation. However, SIH but not MIH decreases anti-oxidative capacity and increases lipid peroxidation in circulation, leading to suppression of vascular endothelial function, causing impairment of vascular haemodynamics.     

褪黑素预处理对抗油酸引起的大鼠急性肺损伤

目的：评估褪黑素预处理对油酸引起的大鼠急性肺损伤的拮抗作用。方法：24只大鼠随机分为生理盐水组、油酸组和褪黑素预处理组3组，检测大鼠肺泡灌洗蛋白、肺的湿干比重、丙二醛、超氧化物岐化酶水平，并进行肺的病理组织学检查。结果：（1）静脉注射0.15 mL/kg油酸引起肺泡灌洗蛋白、肺的湿干比重显著增高（P<0.01），病理组织学检查发现有肺出血、肺水肿、肺泡间隔增厚以及肺泡腔出现炎性细胞，导致严重的急性肺损伤；（2）提前60 min腹腔注射20 mg/kg褪黑素明显减轻上述的症状，与丙二醛的降低（P<0.01）和超氧化物岐化酶的升高（P<0.01）相一致。结论：褪黑素预处理可通过清除和防止自由基的形成，进一步降低肺泡毛细血管膜通透性的增加，从而减轻油酸引起的大鼠急性肺损伤。提示褪黑素可能在急性肺损伤的防治中是有效的。     

Effects of short-term physical training on the liver IGF-I in diabetic rats

To investigate the influence of short-term physical training on IGF-I concentrations in diabetic rats, male wistar rats were distributed into four groups: sedentary control, trained control, sedentary diabetic and trained diabetic. Diabetes was induced by Alloxan (32 mg/kg b.w.) and training protocol consisted of swimming 1 h/day, 5 days/week, during 4 weeks, supporting 5% b.w. At the end of this period, rats were sacrificed and blood was collected for determinations of serum glucose, insulin, albumin, IGF-I and hematocrit. Liver samples were used to determine glycogen, protein, DNA and IGF-I concentrations. Diabetes reduced insulin and IGF-I concentrations in blood and liver protein, ratio protein/DNA and IGF-I concentrations in liver and increased glycemia. Physical training reduced serum glucose and recovered hepatic glycogen stores in diabetic rats and reduced serum and liver IGF-I concentrations. In conclusion, short-term physical training improved the metabolic conditions of diabetic rats, despite of impairing liver and blood IGF-I concentrations.     

Antihyperglycemic and antioxidant activities of alcoholic extract of Commiphora mukul gum resin in streptozotocin induced diabetic rats

Background and objectives: The present study investigated the effect of Commiphora mukul ethanol extract gum resin (CMEEt) on streptozotocin (STZ) induced diabetic rats by measuring fasting blood glucose, plasma insulin, plasma lipid profile, atherogenic index, hepatic lipid peroxidation (LPO), protein oxidation (PO) and activities of enzymatic antioxidants. Methods: Wistar albino rats were divided into 4 groups, normal control group, CM-treated control group, diabetic control group and CM-treated diabetic group. For induction of diabetes, STZ was administered at a dose of 55 mg/kg body weight, meanwhile CM-treated groups were administered CMEEt at a dose of 200 mg/kg body weight for 60 days. Body weight, plasma glucose and insulin levels were determined in different experimental days, after end of the experimental period the plasma lipid profile and antioxidant enzymes were determined in hepatic tissue. Results: Increase in plasma glucose, total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), very low density lipoprotein cholesterol (VLDL-C), hepatic LPO and PO levels with decrease in plasma high density lipoprotein cholesterol (HDL-C), insulin, hepatic reduced glutathione (GSH) content and activities of antioxidant enzymes namely, glutathione peroxidase (GPX), glutathione reductase (GR), glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) were the salient features observed in diabetic rats. On the other hand, oral administration of CMEEt at a dose of 200 mg/kg for 60 days resulted in the prevention of above mentioned abnormalities. Conclusion: The results suggest that CMEEt could be beneficial in the treatment of diabetes, characterized by atherogenous lipoprotein profile, aggravated antioxidant status and impaired glucose metabolism and in their prevention.     

褪黑素对烟雾吸入所致大鼠急性肺损伤的保护作用

目的通过建立褪黑素干预大鼠烟雾吸入性损伤模型,探讨褪黑素对急性肺损伤的保护作用。方法成年清洁级雄性SD大鼠72只随机分为空白组、损伤组和褪黑素组。空白组不做任何处理,损伤组于吸入性损伤处理后腹腔注射1%乙醇生理盐水（10ml/kg）,褪黑素组于吸入性损伤处理后腹腔注射褪黑素（10mg/kg,1次/8h）。三组大鼠分别在3h、12h、24h三个时相腹主动脉取血2ml后处死,动脉血离心后检测肿瘤坏死因子α（TNF-α）、白细胞介素6（IL-6）含量和白细胞介素10（IL-10）。肺组织匀浆测超氧化物歧化酶（SOD）、丙二醛（MDA）、髓过氧化物酶（MPO）的含量。取右下肺组织作病理切片,光镜下观察肺组织病理情况。结果光镜下见空白组大鼠肺泡腔结构完整,壁光滑;损伤组肺泡壁增厚,肺间质炎症细胞浸润;褪黑素组肺组织较损伤组病理表现有所减轻。褪黑素组各时相点血清TNF-α和IL-6含量高于空白组（P〈0.05）,低于损伤组（P〈0.05）。损伤组各时相点IL-10含量与空白组相比无统计学差异（P〉0.05）,而褪黑素组IL-10含量与空白组、损伤组相比均升高（P〈0.05）。褪黑素组各时相点肺组织SOD含量均高于损伤组（P〈0.05）,低于空白组（P〈0.05）。褪黑素组各时相肺组织MDA和MPO含量均高于空白组（P〈0.05）,低于损伤组（P〈0.05）。结论褪黑素可以减轻炎症及氧化应激,对烟雾吸入性损伤所致急性肺损伤发挥一定的保护作用。     

Superoxide dismutase derivative prevents oxidative damage in liver and kidney of rats induced by exhausting exercise

To prevent oxidative tissue damage induced by strenuous exercise in the liver and kidney superoxide dismutase derivative (SM-SOD), which circulated bound to albumin with a half-life of 6 h, was injected intraperitoneally into rats. Exhausting treadmill running caused a significant increase in the activities of xanthine oxidase (XO), and glutathione peroxidase (GPX) in addition to concentrations of thiobarbituric acid-reactive substances (TBARS) in hepatic tissue immediately after running. There was a definite increase in the immunoreactive content of mitochondrial superoxide dismutase (Mn-SOD) 1 day after the running. Meanwhile, the TBARS concentration in the kidney was markedly elevated 3 days after running. The activities of GPX, and catalase in the kidney increased significantly immediately and on days 1 and 3 following the test. The immunoreactive content of Mn-SOD also increased 1 day after running. The exercise induced no significant changes in immunoreactive Cu, Zn-SOD content in either tissue. The administration of SM-SOD provided effective protection against lipid peroxidation, and significantly attenuated the alterations in XO and all the anti-oxidant enzymes, measured. In summary, the present data would suggest that exhausting exercise may induce XO-derived oxidative damage in the liver, while the increase in lipid peroxidation in the kidney might be the result of washout-dependent accumulation of peroxidised metabolites. We found that the administration of SM-SOD provided excellent protection against exercise-induced oxidative stress in both liver and kidney.     

甘草酸二铵对肝纤维化大鼠肝脏脂质过氧化与间质性胶原酶活性的影响

目的：探讨甘草酸二铵影响纤维化肝脏脂质过氧化与间质性胶原酶活性的抗肝纤维化作用机制。 方法： 以四氯化碳(CCl4)皮下注射与高脂肪低蛋白饮食复合因素诱导大鼠肝纤维化模型，而后予以甘草酸二铵口服治疗，正常大鼠与模型对照组给予等量生理盐水。HE染色与胶原染色观察大鼠肝组织炎性坏死与胶原沉积病理改变，按试剂盒方法检测血清肝功能（ALT、AST、Alb与总胆红素等）变化，检测肝组织主要过氧化损伤指标：超氧化物歧化酶（SOD）活性, 丙二醛（MDA）含量，谷胱甘肽（GSH）含量与谷胱甘肽过氧化物酶（GSH-Px）活性，水解法测定肝组织羟脯氨酸含量，酶底物反应法分析肝组织间质性胶原酶活性变化，RT-PCR法分析肝组织Ⅰ型前胶原基因表达。 结果： 与正常大鼠相比，模型大鼠肝脏有明显胶原沉积与肝纤维化，伴有不同程度的肝细胞炎性损伤坏死；甘草酸二铵药物组明显减轻模型大鼠肝组织损伤坏死与胶原沉积等病理变化。模型大鼠肝功能指标,包括血清总胆红素含量、ALT与AST活性、白蛋白含量均明显减少（P<0.01）。药物组大鼠血清总胆红素含量、AST与ALT活性显著低于模型组（P<0.05），而白蛋白含量高于模型组（P<0.05）。此外，药物组大鼠肝组织羟脯氨酸含量(151.3±37.3 μg/g)明显少于模型组(170.9±15.3 μg/g，P<0.05)，Ⅰ型前胶原基因表达弱于模型组（P<0.05）；肝组织MDA含量(1.96±0.23 μmol/g)低于模型组(2.44±0.32 μmol/L, P<0.05)，SOD水平(19.60±0.97 NU/g)高于模型组(20.60±0.33 NU/g，P<0.05)，GSH含量(47.0±9.1 g/g)与GSH-Px活性(53.1±4.1 U/g)高于模型组(41.2±3.5 g/g；46.7±6.1 U/g，P<0.05)；肝组织间质性胶原酶活性(43.89±7.74 U)高于模型组(32.01±2.75 U，P<0.05)。 结论： 甘草酸二铵有明显抗肝纤维化大鼠肝脏脂质过氧化损伤与提高肝组织间质性胶原酶活性的作用，该作用是药物抗肝纤维化的重要机制。     

灯盏花素对糖尿病大鼠肝、肾组织氧化应激的影响

目的：探讨灯盏花素对糖尿病大鼠肝、肾组织氧化应激的影响。方法： 建立STZ诱导的糖尿病模型，随机分3组：正常对照组、模型组、灯盏花素给药组。8周后应用HE、油红O染色对肝组织、PAS染色对肾组织作病理检查。分光光度法检测肝、肾组织丙二醛(MDA)含量及抗氧化物酶活性。结果： HE染色显示模型组部分肝细胞脂肪变性，评分为1.54±0.65，灯盏花素给药组评分为0.55±0.43，差异高度显著(P<0.01)。油红O染色模型组肝组织评分为2.11±0.82，灯盏花素给药组为0.75±0.66，差异高度显著(P<0.01)。模型组大鼠肾重、肾重/体重、24 h尿白蛋白排泄率(AER)与肾小球面积(AG)、肾小球容量(VG) 及系膜区面积(AM)均明显增加，灯盏花素给药组这些改变减轻。灯盏花素给药组肝、肾组织MDA含量明显低于模型组(P<0.05，P<0.01)。超氧化物歧化酶(SOD)、过氧化氢酶(CAT)及谷胱甘肽过氧化物酶(GSH-Px)活性明显高于模型组(P<0.05，P<0.01)。结论： 灯盏花素对糖尿病大鼠肝、肾组织有明显保护作用，其机制部分可能与抑制肝、肾组织氧化应激增加有关。     

胰岛素及格列齐特治疗2型糖尿病大鼠肝脏脂质沉积的机制探讨*

 目的：探讨胰岛素及格列齐特治疗2型糖尿病对大鼠肝脏脂质沉积的影响及机制。方法：制备高脂及链脲佐菌素诱导的2型糖尿病大鼠模型,随机分为糖尿病组、胰岛素组和格列齐特组,并设正常对照组。通过肝脏油红O染色观察其肝细胞脂质沉积情况;ELISA检测血清脂联素水平;实时荧光定量PCR检测肝脏脂联素受体1（AdipoR1）mRNA表达;Western blotting检测肝脏腺苷酸活化蛋白激酶（AMPK）、磷酸化的腺苷酸活化蛋白激酶（Thr172p-AMPK）、固醇调节因子结合蛋白1c（SREBP-1c）、磷酸化的固醇调节因子结合蛋白1c（Ser372p-SREBP1-1c）、乙酰辅酶A羧化酶（ACC）、磷酸化的乙酰辅酶A羧化酶（Ser79p-ACC）和免疫球蛋白结合蛋白（BiP）的表达。结果：糖尿病组肝细胞脂质沉积较正常对照组明显增多,胰岛素和格列齐特治疗后肝细胞脂质沉积明显改善。胰岛素治疗后,血清脂联素的水平及肝脏AdipoR1 mRNA水平较糖尿病组和正常对照组显著升高（P＜0.01）,而格列齐特治疗后两者水平恢复至正常对照组水平。Western blotting结果显示,糖尿病大鼠与正常对照组比较,肝脏Thr172p-AMPK/AMPK和Ser372p-SREBP-1c/SREBP-1c和Ser79p-ACC/ACC表达明显降低（P＜0.01）,BiP表达明显升高（P＜0.01）。胰岛素治疗后,Thr172p-AMPK/AMPK和Ser372p-SREBP-1c/SREBP-1c显著升高（P＜0.01）,Ser79p-ACC/ACC和BiP蛋白表达恢复至正常对照组水平。而格列齐特治疗后Thr172p-AMPK/AMPK和Ser372p-SREBP-1c/SREBP-1c恢复至正常对照组水平,BiP蛋白表达显著下降（P＜0.01）,Ser79p-ACC/ACC与糖尿病组比较无明显改善。结论：胰岛素和格列齐特治疗均能通过激活脂联素-AMPK减轻2型糖尿病大鼠肝脏的脂质沉积。但两者作用的分子机制有所不同。胰岛素激活AMPK,通过抑制SREBP-1c表达、直接磷酸化SREBP-1c抑制SREBP-1c入核等短期和长期的作用以及抑制内质网应激影响SREBP-1c,减少脂质合成;而格列齐特仅通过磷酸化的短期作用和抑制内质网应激对SREBP-1c产生影响,且对脂肪酸氧化无作用。