Home About us Contact
|
Home About us Contact | ||
|
|
||
LETO Rats (leto + rat)
Selected AbstractsA quantitative study of the optic nerve in diabetic mutant, Otsuka Long-Evans Tokushima Fatty (OLETF) ratsCONGENITAL ANOMALIES, Issue 4 2001Kazuhiko Sawada ABSTRACT, Optic nerves of the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, an animal model of non-insulin dependent diabetes mellitus, were examined using quantitative stereological procedures. At 67 weeks of age, OLETF rats showed a mild hyperglycemia: their blood glucose level was 196 ± 93 mg/dl, significantly higher than that of non-diabetic control Long-Evans Tokushima Otsuka (LETO) rats (110 ± 24 mg/dl). However, there were no differences in the cross sectional area of optic nerves (the mean minimum diameter), the total number and mean diameter of both myelinated and non-myelinated fibers, or the thickness of the myelin sheath between OLETF and LETO rats. The results suggested that a mild hyperglycemia in OLETF rats could not cause any morphological changes in the optic nerve. [source] Troglitazone prevents fatty changes of the liver in obese diabetic ratsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 10 2000Dong Mei Jia Abstract Background and Aims: Troglitazone is a newly developed antidiabetic drug and is indicated to be useful for the treatment of patients with type II diabetes mellitus. Recently, however, it became clear that troglitazone could cause liver dysfunction in some patients. In addition, a relationship between the activation of the peroxisome proliferator-activated receptor gamma receptor by troglitazone and colon tumorigenesis has been suggested. The present study was undertaken to examine the effects of long-term administration of troglitazone on the liver and intestine in genetically obese and diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) and control Long-Evans Tokushima Otsuka (LETO) rats. Methods: A troglitazone-rich diet (200 mg/100 g normal chow) or a standard rat chow, free of troglitazone (control), was given to OLETF and LETO rats from 12 or 28 weeks of age until 72 weeks of age. Serum levels of glucose, insulin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were determined at several time points. In addition, histology of the liver and intestine and serum levels of cholesterol and triglycerides were examined at 72 weeks of age. Results: Troglitazone prevented age-related increases in fasting glucose and insulin concentrations in OLETF rats, but had no significant influences on serum levels of AST and ALT in both strains of rats. The liver weights in the control OLETF rats were significantly heavier than in the LETO rats. Troglitazone significantly reduced serum cholesterol and triglyceride levels and the liver weight. However, it had no influence on the large intestine weight and the number of colonic polyps in both OLETF and LETO rats. Sections of the liver from the untreated OLETF rats showed mild fatty changes in the central zone of the hepatic lobule, whereas those from the troglitazone-treated OLETF rats appeared normal with no fat deposition in the hepatocytes. Troglitazone in LETO rats also caused no significant histopathologic changes of the liver tissue. Conclusion: Our present study demonstrated that long-term administration of troglitazone prevents the progress of the metabolic derangement and fatty changes of the liver in genetically determined obese diabetes. [source] Activity of the Chinese prescription Hachimi-jio-gan against renal damage in the Otsuka Long-Evans Tokushima Fatty rat: a model of human type 2 diabetes mellitusJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2006Noriko Yamabe Currently, in Japan, approximately 95% of patients with diabetes mellitus have non-insulin-dependent (type 2) diabetes mellitus (NIDDM), and diabetic nephropathy is a major cause of patients requiring chronic haemodialysis. A previous study showed that Hachimi-jio-gan has a protective effect in rats subjected to subtotal nephrectomy plus streptozotocin injection, a model of insulin-dependent (type 1) diabetic nephropathy. In this study, we used the Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of human NIDDM, to investigate whether long-term administration of Hachimi-jio-gan affects glycaemic control and renal function in NIDDM. Male OLETF rats, aged 22 weeks, were divided into 4 groups of 10 and given Hachimi-jio-gan (50, 100 or 200 mg kg,1 daily) orally or no treatment for 32 weeks. Male Long-Evans Tokushima Otsuka (LETO) rats (n = 6) were used as non-diabetic normal controls. Hachimi-jio-gan reduced hyperglycaemia dose-dependently from 16 weeks of the administration period. Urinary protein excretion decreased significantly from an early stage, and creatinine clearance levels improved at 32 weeks. In addition, the levels of serum glycosylated protein and renal advanced glycation end-products were effectively reduced. Hachimi-jio-gan also significantly reduced the levels of thiobarbituric acid-reactive substances in renal mitochondria, although it showed only a tendency to reduce these in serum. Furthermore, long-term administration of Hachimi-jio-gan reduced renal cortical expression of proteins, such as transforming growth factor-,1 (TGF-,1), fibronectin, inducible nitric oxide synthase and cyclooxygenase-2. The 100- and 200-mg kg,1 daily doses of Hachimi-jio-gan significantly reduced TGF-,1 and fibronectin protein expression to levels below those of LETO rats. These data suggest that Hachimi-jio-gan may have a beneficial effect on the progression of diabetic nephropathy in OLETF rats by attenuating glucose toxicity and renal damage. [source] Effect of AOB, a fermented-grain food supplement, on oxidative stress in type 2 diabetic ratsBIOFACTORS, Issue 2 2007Yukiko Minamiyama Abstract Reactive oxygen species (ROS) play an important role in the pathogenesis of diabetic complications. Antioxidant Biofactor (AOB) is a mixture of commercially available fermented grain foods and has strong antioxidant activity. This study investigated the effect of AOB supplementation of standard rat food on markers of oxidative stress and inflammation in Otsuka Long-Evans Tokushima Fatty (OLETF) rats with type 2 diabetes. Blood glucose, hemoglobin A1c, plasma free fatty acid, triacylglycerol and plasminogen activator inhibitor-1 (PAI-1) were significantly higher in OLETF rats than in non-diabetic control Long-Evans Tokushima Otsuka (LETO) rats at 29 weeks. AOB (6.5% of diet) was given to rats during 29,33 weeks of diabetic phase in OLETF rats. OLETF rats with AOB supplementation showed decreased blood glucose, hemoglobin A1c, triacylgycerol, low density lipoprotein, cholesterol and PAI-1. Mitochondrial ROS production was significantly increased in heart, aorta, liver and renal artery of OLETF rats. Uncoupling protein 2 (UCP2) is known to regulate ROS production. We found aortic UCP2 protein expression increased in OLETF rats, and AOB returned UCP2 expression to normal. Aortic endothelial NO synthase (eNOS) was also increased in OLETF rats more than in LETO rats at 33 weeks. In contrast, phosphorylated vasodilator-stimulated phosphoprotein, an index of the NO-cGMP pathway, was significantly diminished. AOB increased eNOS proteins in LETO and OLETF rats. In conclusion, AOB significantly improved the NO-cGMP pathway via normalizing ROS generation in OLETF rats. The data suggest that dietary supplementation with AOB contributes to nutritional strategies for the prevention and treatment of type 2 diabetes mellitus. [source] | |||||||||||||