目的:探讨葛根芩连汤对非酒精性脂肪性肝炎的干预作用.方法:高脂饲料喂养SD大鼠以制备非酒精性脂肪性肝炎模型,各给药组在造模的同时进行灌胃给药,持续8 wk后取材,血清用比色法对谷草转氨酶(aspartate aminotransferase,AST)、谷丙转氨...目的:探讨葛根芩连汤对非酒精性脂肪性肝炎的干预作用.方法:高脂饲料喂养SD大鼠以制备非酒精性脂肪性肝炎模型,各给药组在造模的同时进行灌胃给药,持续8 wk后取材,血清用比色法对谷草转氨酶(aspartate aminotransferase,AST)、谷丙转氨酶(alanine transaminase,ALT)、总胆固醇(cholesterol total,CHO)、低密度脂蛋白((low density lipoprotein,LDL)、高密度脂蛋白(high density lipoprotein,HDL)、空腹血糖(fasting plasma glucose,FPG)的含量进行检测,用放免法对空腹胰岛素(fasting insulin,F I N S)的含量进行检测,并进行胰岛素抵抗指数(homeostatic model assessment of insulin resistance,HOMA-IR)计算;肝组织制成石蜡切片及冰冻切片进行HE及油红O染色,并根据"非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)活动度积分"对各组肝组织进行NASH评估.结果:与空白组比较,NASH大鼠血清中A S T、A LT、C H O、L D L的含量显著升高(P<0.05或P<0.01),H D L的含量显著降低(P<0.01),HOMA-IR指数显著升高(P<0.05),葛根芩连汤可显著抑制高脂饲料喂养SD大鼠过程中血清AST、ALT、CHO、LDL含量(P<0.01)及HOMA-IR指数的升高(P<0.05)以及HDL含量的降低(P<0.01);HE染色、油红O染色及NAFLD活动度积分结果显示,葛根芩连汤可显著抑制NASH及相关病理变化的发生发展.结论:葛根芩连汤对非酒精性脂肪性肝炎有一定的干预作用,并可改善胰岛素抵抗.展开更多
Aim To investigate the effects of milrinone (a selective phosphodiesteraseIII inhibitor PDE_3 ) on insulin secretion, blood glucose, plasma free fatty acids (FFA) anddose-response relationship, and assess possible eff...Aim To investigate the effects of milrinone (a selective phosphodiesteraseIII inhibitor PDE_3 ) on insulin secretion, blood glucose, plasma free fatty acids (FFA) anddose-response relationship, and assess possible effects of milrinone on glucose metabolism andinsulin sensitivity in conscious rats. Methods The catheterized nonstressed rats were administeredvarious doses of milrinone (1, 5, 25μmoL·kg^(-1)) and were compared with controls. Ahyperinsulinaemic-eugly-caemic clamp was established in counscious rats, andmilrinone(25μmoL·kg^(-1)) and 25% dimethyl sulfoxide (DMSO, as a control) were given at 120 minduring hyperinsulinaemic-euglycaemic clamping. Glucose turnover was determind with by gaschromatograph mass spectrometer (GC-MS). Results After dosing, plasma FFA levels in 3 milrinonegroups significantly increased, compared with the controls and before dosing. The percentages ofelevation of FFA by the different milrinone doses were very similar, 50%, and 52% , 55% for 1, 5,and 25 μmoL·kg^(-1), repectively, at 2 min after dosing. Plasma insulin levels were significantlyelevated in the 5 and 25 μmoL·kg^(-1) groups, and the effect of milrione on glucose concentrationwas detectable only in 25μmoL·kg^(-1) group. During hyperinsulinaemic clamping, there weresignificant increase, in plasma FFA (from 173 +- 15 to 634 +- 87μmoL·kg^(-1)) and hepatic glucoseproduction (HGP), and a significant decrease in glucose infusion rates (GIR) to about 21% and aslight increase in plasma insulin after milrinone treatment. Conclusion Milrinone impaires theability of insulin to suppress lipolysis and HGP, and insulin-mediated glucose utilization inperipheral tissue. Therefore, milrinone administration may induce an acute insulin resistance invivo.展开更多
AIM: To investigate the effects and molecular mechanisms of berberine on improving insulin resistance induced by free fatty acids (FFAs) in 3T3-L1 adipocytes. METHODS: The model of insulin resistance in 3T3-L1 adipocy...AIM: To investigate the effects and molecular mechanisms of berberine on improving insulin resistance induced by free fatty acids (FFAs) in 3T3-L1 adipocytes. METHODS: The model of insulin resistance in 3T3-L1 adipocytes was established by adding palmic acid (0.5 mmol/L) to the culture medium. Berberine treatment was performed at the same time. Glucose uptake rate was determined by the 2-deoxy-[3H]-D-glucose method. The levels of IkB kinase beta (IKKβ) Ser181 phosphorylation, insulin receptor substrate-1(IRS-1) Ser307 phosphorylation, expression of IKKβ, IRS-1, nuclear transcription factor kappaB p65 (NF-κB p65), phosphatidylinositol-3-kinase p85 (PI-3K p85) and glucose transporter 4 (GLUT4) proteins were detected by Western blotting. The distribution of NF-κB p65 proteins inside the adipocytes was observed through confocal laser scanning microscopy (CLSM). RESULTS: After the intervention of palmic acid for 24 h, the insulin-stimulated glucose transport in 3T3-L1 adipocytes was inhibited by 67%. Meanwhile, the expression of IRS-1 and PI-3K p85 protein was reduced, while the levels of IKKβ Ser181 and IRS-1 Ser307 phosphorylation, and nuclear translocation of NF-κB p65 protein were increased. However, the above indexes, which indicated the existence of insulin resistance, were reversed by berberine although the expression of GLUT4, IKKβ and total NF-κB p65 protein were not changed during this study. CONCLUSION: Insulin resistance induced by FFAs in 3T3-L1 adipocytes can be improved by berberine. Berberine reversed free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ.展开更多
Objective： The prevalence of non-alcoholic fatty liver disease （NAFLD） has markedly increased. Insulin resistance has been implicated in the pathogenesis of NAFLD. This study was aimed at observing the relationship...Objective： The prevalence of non-alcoholic fatty liver disease （NAFLD） has markedly increased. Insulin resistance has been implicated in the pathogenesis of NAFLD. This study was aimed at observing the relationship between insulin resistance and NAFLD, and evaluating the role of pioglitazone （PGZ） acting as insulin-sensitizing agents in the prevention and treatment of rat fatty liver induced by high fat feeding. Methods： The rats were separated randomly into 6 groups： model group Ⅰ were fed high fat diet for 8 weeks, PGZ prevention group were given PGZ 4 mg/（kg.d） simultaneously, while control group Ⅰ were fed normal food for 8 weeks; model group Ⅱ were fed high fat diet for 16 weeks, PGZ treatment group were given PGZ 4 mg/（kg.d） orally simultaneous with high fat diet for 8 weeks after high fat feeding for 8 weeks, control group Ⅱ were fed normal food for 16 weeks. The rats were sacrificed after 8 weeks and 16 weeks respectively. Liver weight, body weight, serum activities of alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, alkaline phosphatase （ALP）, tumor necrosis factor alpha （TNF-α）, fasting blood glucose （FBG）, fasting plasma insulin （FINS）, HOMA （homeostasis model assessment） insulin resistance index （HOMA-IR）, and the liver histology of rats of all groups were assayed. Results： After 8 weeks, the liver in model group Ⅰ showed typical steatosis, accompanied with mild to moderate lobular inflammatory cell infiltration, liver indexes and serum levels of ALT, AST, ALP, TNF-α were significantly increased （P〈0.05） compared with control group Ⅰ. Whereas, the degree of hepatic injury was attenuated in PGZ prevention group, liver indexes and serum levels of ALT, ALP were significantly decreased （P〈0.05） compared with model group Ⅰ. After 16 weeks, notable steatosis, and lobular inflammation were observed in model group Ⅱ rat liver, while the degree of hepatic injury was attenuated in the PGZ treatment group. Liver index, serum levels ofALT, AST, ALP, FINS and HOMA-IR were significantly increased （P〈0.05） in model group Ⅱ compared with control group Ⅱ. Whereas, in PGZ treatment group, serum levels of AST and FINS showed decreasing tendency, liver indexes, serum levels of ALT, ALP, TNF-α and HOMA-IR were significantly decreased compared with model group Ⅱ. Conclusion： Insulin resistance plays a role in the pathogenesis of NAFLD in rats. Pioglitazone can attenuate insulin resistance and biochemical and histological injury in high fat-induced fatty liver in rats.展开更多
Nonalcoholic steatohepatitis (NASH) is an important indication for liver transplantation in many Western countries. Obesity and insulin resistance are the two most common risk factors for NASH, which can lead to recur...Nonalcoholic steatohepatitis (NASH) is an important indication for liver transplantation in many Western countries. Obesity and insulin resistance are the two most common risk factors for NASH, which can lead to recurrent NASH after liver transplantation. There is currently no approved therapy for NASH, and treatment is directed at risk factor modification and lifestyle changes. Betaine has been used for NASH, with mixed results, and may show promise in conjunction with other agents in clinical trials.展开更多
Non-alcoholic fatty liver disease (NAFLD) comprising hepatic steatosis,non-alcoholic steatohepatitis (NASH),and progressive liver fibrosis is considered the most common liver disease in western countries.Fatty liver i...Non-alcoholic fatty liver disease (NAFLD) comprising hepatic steatosis,non-alcoholic steatohepatitis (NASH),and progressive liver fibrosis is considered the most common liver disease in western countries.Fatty liver is more prevalent in overweight than normal-weight people and liver fat positively correlates with hepatic insulin resistance.Hepatic steatosis is regarded as a benign stage of NAFLD but may progress to NASH in a subgroup of patients.Besides liver biopsy no diagnostic tools to identify patients with NASH are available,and no effective treatment has been established.Visceral obesity is a main risk factor for NAFLD and inappropriate storage of triglycerides in adipocytes and higher concentrations of free fatty acids may add to increased hepatic lipid storage,insulin resistance,and progressive liver damage.Most of the adipose tissue-derived proteins are elevated in obesity and may contribute to systemic inflammation and liver damage.Adiponectin is highly abundant in human serum but its levels are reduced in obesity and are even lower in patients with hepatic steatosis or NASH.Adiponectin antagonizes excess lipid storage in the liver and protects from inflammation and fibrosis.This review aims to give a short survey on NAFLD and the hepatoprotective effects of adiponectin.展开更多
There are several cofactors which affect body iron metabolism and accelerate iron overload. Alcohol and hepatic viral infections are the most typical examples for clarifying the role of cofactors in iron overload. In ...There are several cofactors which affect body iron metabolism and accelerate iron overload. Alcohol and hepatic viral infections are the most typical examples for clarifying the role of cofactors in iron overload. In these conditions, iron is deposited in hepatocytes and Kupffer cells and reactive oxygen species （ROS） produced through Fenton reaction have key role to facilitate cellular uptake of transferrin-bound iron. Furthermore, hepcidin, antimicrobial peptide produced mainly in the liver is also responsible for intestinal iron absorption and reticuloendothelial iron release. In patients with ceruloplasmin deficiency, anemia and secondary iron overload in liver and neurodegeneration are reported. Furthermore, there is accumulating evidence that fatty acid accumulation without alcohol and obesity itself modifies iron overload states. Ineffective erythropoiesis is also an important factor to accelerate iron overload, which is associated with diseases such as thalassemia and myelodysplastic syndrome. When this condition persists, the dietary iron absorption is increased due to the increment of bone marrow erythropoiesis and tissue iron overload will thereafter occurs. In porphyria cutanea tarda, iron is secondarily accumulated in the liver.展开更多
AIM: Obesity and insulin resistance (IR) are closely related to hepatic steatosis (HS), and adiponectin is a hepatic insulin sensitizer that has important effects in liver function. This study aims at investigating th...AIM: Obesity and insulin resistance (IR) are closely related to hepatic steatosis (HS), and adiponectin is a hepatic insulin sensitizer that has important effects in liver function. This study aims at investigating the relationship between serum adiponectin concentration and the presence of HS. METHODS: We carried out a cross-sectional study in a check-up unit of a University Hospital in Mexico City. We enrolled 196 subjects, comprising 98 subjects with HS (27 women, 71 men) and 98 controls (37 women and 61 men). Anthropometric, metabolic and biochemical variables were measured in the two groups. Serum adiponectin and leptin concentrations were determined, their association with grade of HS tested, and concentrations, according to quartiles, compared between cases and controls. X2 analysis for linear trends was used to test for a dose-response relationship and logistic regression analysis was conducted to test for a protective effect of adiponectin. RESULTS: The HS subjects were older and more obese than controls, with a central obesity pattern. In the fourth quartile of adiponectin concentrations, HS was less common and severe. In a multivariate model of the fourth quartile of the adiponectin concentrations, we observed a protective effect (OR = 0.17, 95%CI: 0.04-0.67, P= 0.01). In subjects with more severe HS, we observed higher leptin concentrations, and caloric intakes, total fat and iron consumption were higher than in controls. CONCLUSION: The results of the present study suggest that a high serum concentration of adiponectin is associated with a protective effect against HS.展开更多
Sedentary lifestyle and poor dietary choices are leading to a weight gain epidemic in westernized countries, subsequently increasing the risk for developing the metabolic syndrome and nonalcoholic fatty liver disease ...Sedentary lifestyle and poor dietary choices are leading to a weight gain epidemic in westernized countries, subsequently increasing the risk for developing the metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). NAFLD is estimated to affect approximate 30% of the general US population and is considered the hepatic manifestation of the metabolic syndrome. Recent findings linking the components of the metabolic syndrome with NAFLD and the progression to nonalcoholic steatohepatitis (NASH) will be reviewed; in particular, the role of visceral adipose tissue, insulin resistance, and adipocytokines in the exacerbation of these conditions. While no therapy has been proven effective for treating NAFLD/NASH, common recommendations will be discussed.展开更多
AIMTo evaluate the effect of sitagliptin vs placebo on histologic and non-histologic parameters of non-alcoholic steatohepatitis (NASH).METHODSTwelve patients with biopsy-proven NASH were randomized to sitagliptin (10...AIMTo evaluate the effect of sitagliptin vs placebo on histologic and non-histologic parameters of non-alcoholic steatohepatitis (NASH).METHODSTwelve patients with biopsy-proven NASH were randomized to sitagliptin (100 mg daily) (n = 6) or placebo (n = 6) for 24 wk. The primary outcome was improvement in liver fibrosis after 24 wk. Secondary outcomes included evaluation of changes in NAFLD activity score (NAS), individual components of NAS (hepatocyte ballooning, lobular inflammation, and steatosis), glycemic control and insulin resistance [including measurements of glycated hemoglobin (HbA1C) and adipocytokines], lipid profile including free fatty acids, adipose distribution measured using magnetic resonance imaging (MRI), and thrombosis markers (platelet aggregation and plasminogen activator inhibitor 1 levels). We also sought to determine the correlation between changes in hepatic fat fraction (%) [as measured using the Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL) MRI technique] and changes in hepatic steatosis on liver biopsy.RESULTSSitagliptin was not significantly better than placebo at reducing liver fibrosis score as measured on liver biopsy (mean difference between sitagliptin and placebo arms, 0.40, P = 0.82). There were no significant improvements evident with the use of sitagliptin vs placebo for the secondary histologic outcomes of NAS total score as well as for the individual components of NAS. Compared to baseline, those patients who received sitagliptin demonstrated improved HbA1C (6.7% ± 0.4% vs 7.9% ± 1.0%, P = 0.02), and trended towards improved adiponectin levels (4.7 ± 3.5 μg/mL vs 3.9 ± 2.7 μg/mL, P = 0.06) and triglyceride levels (1.26 ± 0.43 mmol/L vs 2.80 ± 1.64 mmol/L, P = 0.08). However, when compared with placebo, sitagliptin did not cause a statistically significant improvement in HbA1C (mean difference, -0.7%, P = 0.19) nor triglyceride levels (mean difference -1.10 mmol/L, P = 0.19) but did trend towards improved adiponectin levels only (mean difference, 0.60 μg/mL, P = 0.095). No significant changes in anthropometrics, liver enzymes, other adipocytokines, lipid profile, thrombosis parameters, or adipose distribution were demonstrated. The MRI IDEAL procedure correlated well with steatosis scores obtained on liver biopsy in both groups at baseline and post-treatment, and the Spearman correlation coefficients ranged from r = 0.819 (baseline) to r = 0.878 (post-treatment), P = 0.002.CONCLUSIONSitagliptin does not improve fibrosis score or NAS after 24 wk of therapy. The MRI IDEAL technique may be useful for non-invasive measurement of hepatic steatosis.展开更多
The clinical implications of non-alcoholic fatty liver diseases(NAFLD)derive from their potential to progress to fibrosis and cirrhosis.Inappropriate dietary fat intake,excessive intake of soft drinks,insulin resistan...The clinical implications of non-alcoholic fatty liver diseases(NAFLD)derive from their potential to progress to fibrosis and cirrhosis.Inappropriate dietary fat intake,excessive intake of soft drinks,insulin resistance and increased oxidative stress results in increased free fatty acid delivery to the liver and increased hepatic triglyceride(TG)accumulation.An olive oil-rich diet decreases accumulation of TGs in the liver,improves postprandial TGs,glucose and glucagonlike peptide-1 responses in insulin-resistant subjects, and upregulates glucose transporter-2 expression in the liver.The principal mechanisms include:decreased nuclear factor-kappaB activation,decreased lowdensity lipoprotein oxidation,and improved insulin resistance by reduced production of inflammatory cytokines(tumor necrosis factor,interleukin-6)and improvement of jun N-terminal kinase-mediated phosphorylation of insulin receptor substrate-1.The beneficial effect of the Mediterranean diet is derived from monounsaturated fatty acids,mainly from olive oil.In this review,we describe the dietary sources of the monounsaturated fatty acids,the composition of olive oil,dietary fats and their relationship to insulin resistance and postprandial lipid and glucose responses in non-alcoholic steatohepatitis,clinical and experimental studies that assess the relationship between olive oil and NAFLD,and the mechanism by which olive oil ameliorates fatty liver,and we discuss future perspectives.展开更多
文摘目的:探讨葛根芩连汤对非酒精性脂肪性肝炎的干预作用.方法:高脂饲料喂养SD大鼠以制备非酒精性脂肪性肝炎模型,各给药组在造模的同时进行灌胃给药,持续8 wk后取材,血清用比色法对谷草转氨酶(aspartate aminotransferase,AST)、谷丙转氨酶(alanine transaminase,ALT)、总胆固醇(cholesterol total,CHO)、低密度脂蛋白((low density lipoprotein,LDL)、高密度脂蛋白(high density lipoprotein,HDL)、空腹血糖(fasting plasma glucose,FPG)的含量进行检测,用放免法对空腹胰岛素(fasting insulin,F I N S)的含量进行检测,并进行胰岛素抵抗指数(homeostatic model assessment of insulin resistance,HOMA-IR)计算;肝组织制成石蜡切片及冰冻切片进行HE及油红O染色,并根据"非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)活动度积分"对各组肝组织进行NASH评估.结果:与空白组比较,NASH大鼠血清中A S T、A LT、C H O、L D L的含量显著升高(P<0.05或P<0.01),H D L的含量显著降低(P<0.01),HOMA-IR指数显著升高(P<0.05),葛根芩连汤可显著抑制高脂饲料喂养SD大鼠过程中血清AST、ALT、CHO、LDL含量(P<0.01)及HOMA-IR指数的升高(P<0.05)以及HDL含量的降低(P<0.01);HE染色、油红O染色及NAFLD活动度积分结果显示,葛根芩连汤可显著抑制NASH及相关病理变化的发生发展.结论:葛根芩连汤对非酒精性脂肪性肝炎有一定的干预作用,并可改善胰岛素抵抗.
文摘Aim To investigate the effects of milrinone (a selective phosphodiesteraseIII inhibitor PDE_3 ) on insulin secretion, blood glucose, plasma free fatty acids (FFA) anddose-response relationship, and assess possible effects of milrinone on glucose metabolism andinsulin sensitivity in conscious rats. Methods The catheterized nonstressed rats were administeredvarious doses of milrinone (1, 5, 25μmoL·kg^(-1)) and were compared with controls. Ahyperinsulinaemic-eugly-caemic clamp was established in counscious rats, andmilrinone(25μmoL·kg^(-1)) and 25% dimethyl sulfoxide (DMSO, as a control) were given at 120 minduring hyperinsulinaemic-euglycaemic clamping. Glucose turnover was determind with by gaschromatograph mass spectrometer (GC-MS). Results After dosing, plasma FFA levels in 3 milrinonegroups significantly increased, compared with the controls and before dosing. The percentages ofelevation of FFA by the different milrinone doses were very similar, 50%, and 52% , 55% for 1, 5,and 25 μmoL·kg^(-1), repectively, at 2 min after dosing. Plasma insulin levels were significantlyelevated in the 5 and 25 μmoL·kg^(-1) groups, and the effect of milrione on glucose concentrationwas detectable only in 25μmoL·kg^(-1) group. During hyperinsulinaemic clamping, there weresignificant increase, in plasma FFA (from 173 +- 15 to 634 +- 87μmoL·kg^(-1)) and hepatic glucoseproduction (HGP), and a significant decrease in glucose infusion rates (GIR) to about 21% and aslight increase in plasma insulin after milrinone treatment. Conclusion Milrinone impaires theability of insulin to suppress lipolysis and HGP, and insulin-mediated glucose utilization inperipheral tissue. Therefore, milrinone administration may induce an acute insulin resistance invivo.
基金The National Natural Science Foundation of China, No. 30371816
文摘AIM: To investigate the effects and molecular mechanisms of berberine on improving insulin resistance induced by free fatty acids (FFAs) in 3T3-L1 adipocytes. METHODS: The model of insulin resistance in 3T3-L1 adipocytes was established by adding palmic acid (0.5 mmol/L) to the culture medium. Berberine treatment was performed at the same time. Glucose uptake rate was determined by the 2-deoxy-[3H]-D-glucose method. The levels of IkB kinase beta (IKKβ) Ser181 phosphorylation, insulin receptor substrate-1(IRS-1) Ser307 phosphorylation, expression of IKKβ, IRS-1, nuclear transcription factor kappaB p65 (NF-κB p65), phosphatidylinositol-3-kinase p85 (PI-3K p85) and glucose transporter 4 (GLUT4) proteins were detected by Western blotting. The distribution of NF-κB p65 proteins inside the adipocytes was observed through confocal laser scanning microscopy (CLSM). RESULTS: After the intervention of palmic acid for 24 h, the insulin-stimulated glucose transport in 3T3-L1 adipocytes was inhibited by 67%. Meanwhile, the expression of IRS-1 and PI-3K p85 protein was reduced, while the levels of IKKβ Ser181 and IRS-1 Ser307 phosphorylation, and nuclear translocation of NF-κB p65 protein were increased. However, the above indexes, which indicated the existence of insulin resistance, were reversed by berberine although the expression of GLUT4, IKKβ and total NF-κB p65 protein were not changed during this study. CONCLUSION: Insulin resistance induced by FFAs in 3T3-L1 adipocytes can be improved by berberine. Berberine reversed free-fatty-acid-induced insulin resistance in 3T3-L1 adipocytes through targeting IKKβ.
文摘Objective： The prevalence of non-alcoholic fatty liver disease （NAFLD） has markedly increased. Insulin resistance has been implicated in the pathogenesis of NAFLD. This study was aimed at observing the relationship between insulin resistance and NAFLD, and evaluating the role of pioglitazone （PGZ） acting as insulin-sensitizing agents in the prevention and treatment of rat fatty liver induced by high fat feeding. Methods： The rats were separated randomly into 6 groups： model group Ⅰ were fed high fat diet for 8 weeks, PGZ prevention group were given PGZ 4 mg/（kg.d） simultaneously, while control group Ⅰ were fed normal food for 8 weeks; model group Ⅱ were fed high fat diet for 16 weeks, PGZ treatment group were given PGZ 4 mg/（kg.d） orally simultaneous with high fat diet for 8 weeks after high fat feeding for 8 weeks, control group Ⅱ were fed normal food for 16 weeks. The rats were sacrificed after 8 weeks and 16 weeks respectively. Liver weight, body weight, serum activities of alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, alkaline phosphatase （ALP）, tumor necrosis factor alpha （TNF-α）, fasting blood glucose （FBG）, fasting plasma insulin （FINS）, HOMA （homeostasis model assessment） insulin resistance index （HOMA-IR）, and the liver histology of rats of all groups were assayed. Results： After 8 weeks, the liver in model group Ⅰ showed typical steatosis, accompanied with mild to moderate lobular inflammatory cell infiltration, liver indexes and serum levels of ALT, AST, ALP, TNF-α were significantly increased （P〈0.05） compared with control group Ⅰ. Whereas, the degree of hepatic injury was attenuated in PGZ prevention group, liver indexes and serum levels of ALT, ALP were significantly decreased （P〈0.05） compared with model group Ⅰ. After 16 weeks, notable steatosis, and lobular inflammation were observed in model group Ⅱ rat liver, while the degree of hepatic injury was attenuated in the PGZ treatment group. Liver index, serum levels ofALT, AST, ALP, FINS and HOMA-IR were significantly increased （P〈0.05） in model group Ⅱ compared with control group Ⅱ. Whereas, in PGZ treatment group, serum levels of AST and FINS showed decreasing tendency, liver indexes, serum levels of ALT, ALP, TNF-α and HOMA-IR were significantly decreased compared with model group Ⅱ. Conclusion： Insulin resistance plays a role in the pathogenesis of NAFLD in rats. Pioglitazone can attenuate insulin resistance and biochemical and histological injury in high fat-induced fatty liver in rats.
文摘Nonalcoholic steatohepatitis (NASH) is an important indication for liver transplantation in many Western countries. Obesity and insulin resistance are the two most common risk factors for NASH, which can lead to recurrent NASH after liver transplantation. There is currently no approved therapy for NASH, and treatment is directed at risk factor modification and lifestyle changes. Betaine has been used for NASH, with mixed results, and may show promise in conjunction with other agents in clinical trials.
基金Supported by The Faculty of Medicine of the University of Regensburg (ReForM C)The Deutsche Forschungsgemein-schaft
文摘Non-alcoholic fatty liver disease (NAFLD) comprising hepatic steatosis,non-alcoholic steatohepatitis (NASH),and progressive liver fibrosis is considered the most common liver disease in western countries.Fatty liver is more prevalent in overweight than normal-weight people and liver fat positively correlates with hepatic insulin resistance.Hepatic steatosis is regarded as a benign stage of NAFLD but may progress to NASH in a subgroup of patients.Besides liver biopsy no diagnostic tools to identify patients with NASH are available,and no effective treatment has been established.Visceral obesity is a main risk factor for NAFLD and inappropriate storage of triglycerides in adipocytes and higher concentrations of free fatty acids may add to increased hepatic lipid storage,insulin resistance,and progressive liver damage.Most of the adipose tissue-derived proteins are elevated in obesity and may contribute to systemic inflammation and liver damage.Adiponectin is highly abundant in human serum but its levels are reduced in obesity and are even lower in patients with hepatic steatosis or NASH.Adiponectin antagonizes excess lipid storage in the liver and protects from inflammation and fibrosis.This review aims to give a short survey on NAFLD and the hepatoprotective effects of adiponectin.
文摘There are several cofactors which affect body iron metabolism and accelerate iron overload. Alcohol and hepatic viral infections are the most typical examples for clarifying the role of cofactors in iron overload. In these conditions, iron is deposited in hepatocytes and Kupffer cells and reactive oxygen species （ROS） produced through Fenton reaction have key role to facilitate cellular uptake of transferrin-bound iron. Furthermore, hepcidin, antimicrobial peptide produced mainly in the liver is also responsible for intestinal iron absorption and reticuloendothelial iron release. In patients with ceruloplasmin deficiency, anemia and secondary iron overload in liver and neurodegeneration are reported. Furthermore, there is accumulating evidence that fatty acid accumulation without alcohol and obesity itself modifies iron overload states. Ineffective erythropoiesis is also an important factor to accelerate iron overload, which is associated with diseases such as thalassemia and myelodysplastic syndrome. When this condition persists, the dietary iron absorption is increased due to the increment of bone marrow erythropoiesis and tissue iron overload will thereafter occurs. In porphyria cutanea tarda, iron is secondarily accumulated in the liver.
文摘AIM: Obesity and insulin resistance (IR) are closely related to hepatic steatosis (HS), and adiponectin is a hepatic insulin sensitizer that has important effects in liver function. This study aims at investigating the relationship between serum adiponectin concentration and the presence of HS. METHODS: We carried out a cross-sectional study in a check-up unit of a University Hospital in Mexico City. We enrolled 196 subjects, comprising 98 subjects with HS (27 women, 71 men) and 98 controls (37 women and 61 men). Anthropometric, metabolic and biochemical variables were measured in the two groups. Serum adiponectin and leptin concentrations were determined, their association with grade of HS tested, and concentrations, according to quartiles, compared between cases and controls. X2 analysis for linear trends was used to test for a dose-response relationship and logistic regression analysis was conducted to test for a protective effect of adiponectin. RESULTS: The HS subjects were older and more obese than controls, with a central obesity pattern. In the fourth quartile of adiponectin concentrations, HS was less common and severe. In a multivariate model of the fourth quartile of the adiponectin concentrations, we observed a protective effect (OR = 0.17, 95%CI: 0.04-0.67, P= 0.01). In subjects with more severe HS, we observed higher leptin concentrations, and caloric intakes, total fat and iron consumption were higher than in controls. CONCLUSION: The results of the present study suggest that a high serum concentration of adiponectin is associated with a protective effect against HS.
文摘Sedentary lifestyle and poor dietary choices are leading to a weight gain epidemic in westernized countries, subsequently increasing the risk for developing the metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). NAFLD is estimated to affect approximate 30% of the general US population and is considered the hepatic manifestation of the metabolic syndrome. Recent findings linking the components of the metabolic syndrome with NAFLD and the progression to nonalcoholic steatohepatitis (NASH) will be reviewed; in particular, the role of visceral adipose tissue, insulin resistance, and adipocytokines in the exacerbation of these conditions. While no therapy has been proven effective for treating NAFLD/NASH, common recommendations will be discussed.
基金the Physicians’Services Incorporated Foundation 10q2083(Joy TR and Beaton MD)Academic Medical Organization of Southwestern Ontario,No.F10-002(Beaton MD)+1 种基金partly funded through academic research funds from the Program of Experimental Medicine(Joy TR)Department of Medicine Academic Funds(Joy TR)from Western University,London,Ontario,Canada
文摘AIMTo evaluate the effect of sitagliptin vs placebo on histologic and non-histologic parameters of non-alcoholic steatohepatitis (NASH).METHODSTwelve patients with biopsy-proven NASH were randomized to sitagliptin (100 mg daily) (n = 6) or placebo (n = 6) for 24 wk. The primary outcome was improvement in liver fibrosis after 24 wk. Secondary outcomes included evaluation of changes in NAFLD activity score (NAS), individual components of NAS (hepatocyte ballooning, lobular inflammation, and steatosis), glycemic control and insulin resistance [including measurements of glycated hemoglobin (HbA1C) and adipocytokines], lipid profile including free fatty acids, adipose distribution measured using magnetic resonance imaging (MRI), and thrombosis markers (platelet aggregation and plasminogen activator inhibitor 1 levels). We also sought to determine the correlation between changes in hepatic fat fraction (%) [as measured using the Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL) MRI technique] and changes in hepatic steatosis on liver biopsy.RESULTSSitagliptin was not significantly better than placebo at reducing liver fibrosis score as measured on liver biopsy (mean difference between sitagliptin and placebo arms, 0.40, P = 0.82). There were no significant improvements evident with the use of sitagliptin vs placebo for the secondary histologic outcomes of NAS total score as well as for the individual components of NAS. Compared to baseline, those patients who received sitagliptin demonstrated improved HbA1C (6.7% ± 0.4% vs 7.9% ± 1.0%, P = 0.02), and trended towards improved adiponectin levels (4.7 ± 3.5 μg/mL vs 3.9 ± 2.7 μg/mL, P = 0.06) and triglyceride levels (1.26 ± 0.43 mmol/L vs 2.80 ± 1.64 mmol/L, P = 0.08). However, when compared with placebo, sitagliptin did not cause a statistically significant improvement in HbA1C (mean difference, -0.7%, P = 0.19) nor triglyceride levels (mean difference -1.10 mmol/L, P = 0.19) but did trend towards improved adiponectin levels only (mean difference, 0.60 μg/mL, P = 0.095). No significant changes in anthropometrics, liver enzymes, other adipocytokines, lipid profile, thrombosis parameters, or adipose distribution were demonstrated. The MRI IDEAL procedure correlated well with steatosis scores obtained on liver biopsy in both groups at baseline and post-treatment, and the Spearman correlation coefficients ranged from r = 0.819 (baseline) to r = 0.878 (post-treatment), P = 0.002.CONCLUSIONSitagliptin does not improve fibrosis score or NAS after 24 wk of therapy. The MRI IDEAL technique may be useful for non-invasive measurement of hepatic steatosis.
文摘The clinical implications of non-alcoholic fatty liver diseases(NAFLD)derive from their potential to progress to fibrosis and cirrhosis.Inappropriate dietary fat intake,excessive intake of soft drinks,insulin resistance and increased oxidative stress results in increased free fatty acid delivery to the liver and increased hepatic triglyceride(TG)accumulation.An olive oil-rich diet decreases accumulation of TGs in the liver,improves postprandial TGs,glucose and glucagonlike peptide-1 responses in insulin-resistant subjects, and upregulates glucose transporter-2 expression in the liver.The principal mechanisms include:decreased nuclear factor-kappaB activation,decreased lowdensity lipoprotein oxidation,and improved insulin resistance by reduced production of inflammatory cytokines(tumor necrosis factor,interleukin-6)and improvement of jun N-terminal kinase-mediated phosphorylation of insulin receptor substrate-1.The beneficial effect of the Mediterranean diet is derived from monounsaturated fatty acids,mainly from olive oil.In this review,we describe the dietary sources of the monounsaturated fatty acids,the composition of olive oil,dietary fats and their relationship to insulin resistance and postprandial lipid and glucose responses in non-alcoholic steatohepatitis,clinical and experimental studies that assess the relationship between olive oil and NAFLD,and the mechanism by which olive oil ameliorates fatty liver,and we discuss future perspectives.
