• The Korean Journal of Physiology and Pharmacology
• /
• v.16 no.3
• /
• pp.181-186
• /
• 2012

Fenofibrate is a selective peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) activator and is prescribed to treat hyperlipidemia. The mechanism through which $PPAR{\alpha}$ agonists reduce food intake, body weight, and adiposity remains unclear. One explanation for the reduction of food intake is that fenofibrate promotes fatty acid oxidation and increases the production of ketone bodies upon a standard experimental dose of the drug (100~300 mg/kg/day). We observed that low-dose treatment of fenofibrate (30 mg/kg/day), which does not cause significant changes in ketone body synthesis, reduced food intake in Long-Evans Tokushima (LETO) rats. LETO rats are the physiologically normal controls for Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which are obese and cholecystokinin (CCK)-A receptor deficient. We hypothesized that the reduced food intake by fenofibrate-treated LETO rats may be associated with CCK production. To investigate the anorexic effects of fenofibrate in vivo and to determine whether CCK production may be involved, we examined the amount of food intake and CCK production. Fenofibrate-treated OLETF rats did not significantly change their food intake while LETO rats decreased their food intake. Treatment of fenofibrate increased CCK synthesis in the duodenal epithelial cells of both LETO and OLETF rats. The absence of a change in the food intake of OLETF rats, despite the increase in CCK production, may be explained by the absence of CCK-A receptors. Contrary to the OLETF rats, LETO rats, which have normal CCK receptors, presented a decrease in food intake and an increase in CCK production. These results suggest that reduced food intake by fenofibrate treatment may be associated with CCK production.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.6
• /
• pp.696-702
• /
• 2007

This study was performed to investigate the antihyperglycemic effect of green tea extracts (GTE) in diabetic rats. Experimental animals used were alloxan-induced diabetic Sprague-Dawley (SD) rats; as a model of type 1 diabetes mellitus and Otsuka Long Evans Tokushima fatty (OLETF) rats, and as a model of type 2 diabetes mellitus. Animals were randomly assigned either to continue the ad libitum diet or begin a green tea extracts (GTE) contained diet. GTE extracted from green tea was supplemented in the diet (2%). Body weight, food intake, and blood glucose concentration were recorded for 4 weeks. Animals were killed and glucose, triglyceride, and asparate aminotransferase (AST) were analysed in blood. Food intake was not affected by GTE in both alloxan.induced diabetic and OLETF rats but body weight was slightly decreased by GTE in OLETF rats. The blood glucose concentration was markedly decreased by GTE supplementation in both alloxan-induced diabetic and OLETF rats; however, triglyceride and AST levels in serum of GTE treated animals were not changed. This study shows that GTE beneficially modulate blood glucose concentration in diabetic animals. Dietary supplementation with GTE could potentially contribute to nutritional strategies for the treatment of diabetes mellitus.

• Biomedical Science Letters
• /
• v.17 no.4
• /
• pp.273-281
• /
• 2011

Our previous study demonstrated that the Korean traditional medicine Gyeongshingangjeehwan (GGEx) inhibits obesity and insulin resistance in obese type 2 diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. We investigated whether GGEx may affect AMP-activated protein kinase ${\alpha}$ ($AMPK{\alpha}$) since $AMPK{\alpha}$ activation is known to stimulate fatty acid oxidation in skeletal muscle of obese rodents. After OLETF rats were treated with GGEx, we studied the effects of GGEx on $AMPK{\alpha}$ and acetyl-CoA carboxylase (ACC) phosphorylation, and the expression of $AMPK{\alpha}$, $PPAR{\alpha}$, and $PPAR{\alpha}$ target genes. The effects of GGEx on mRNA expression of the above genes were also measured in C2C12 skeletal muscle cells. Administration of GGEx to OLETF rats for 8 weeks increased phosphorylation of $AMPK{\alpha}$ and ACC in skeletal muscle. GGEx also elevated skeletal muscle mRNA levels of $AMPK{\alpha}1$ and $AMPK{\alpha}2$ as well as $PPAR{\alpha}$ and its target genes. Consistent with the in vivo data, similar activation of genes was observed in GGEx-treated C2C12 cells. These results suggest that GGEx stimulates skeletal muscle $AMPK{\alpha}$ and $PPAR{\alpha}$ activation, leading to alleviation of obesity and related disorders.

• Journal of Life Science
• /
• v.22 no.5
• /
• pp.634-641
• /
• 2012

It was reported that the novel compounds (LP9M80-H) of $Liriope$ $platyphylla$ regulate glucose transporter (Glut) biosynthesis by activating the insulin-signaling pathway in the liver and brain of ICR mice. To investigate the therapeutic effects of LP9M80-H on the pathology of diabetes and obesity, alterations of key factors related to symptoms were analyzed in the Otsuka Long Evans Tokushima Fatty (OLETF) rats treated with LP9M80-H for 2 weeks. The abdominal fat masses in the LP9M80-H-treated group were lower than the vehicle-treated group, although there was no difference in body weight between the two groups. Additionally, when compared to the vehicle-treated group, LP9M80-H treatment induced a significant decrease in glucose levels and an increase in the insulin concentration in the blood of OLETF rats. A high level of insulin protein was also detected in pancreatic ${\beta}$ cells of LP9M80-H-treated OLETF rats. A significant reduction in the concentration of lipids and adiponectin was detected only in LP9M80-H-treated OLETF rats. Furthermore, the expression of insulin receptor ${\beta}$ and the insulin receptor substrate (IRS) was dramatically decreased in LP9M80-H-treated OLETF rats compared to the vehicle-treated group. Of the glucose transporters located downstream of the insulin-signaling pathway, glucose transporters (Glut) -2 and -3 were significantly decreased in LP9M80-H-treated OLETF rats, while the level of Glut-4 was maintained under all conditions. Therefore, these results suggest that LP9M80-H may contribute to relieving symptoms of diabetes and obesity through glucose homeostasis and regulation of lipid concentration.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.6
• /
• pp.703-707
• /
• 2007

This study was performed to investigate the effect of silk protein hydrolysates hydrolyzed by protease on blood glucose level, serum insulin and leptin secretion in the OLETF rats. Twenty seven week-old-male OLETF rats were divided in three groups: diabetic control, 0.5% and 0.8% silk protein hydrolysates groups that were fed daily for 19 weeks. Body weight increased in the 0.5% and 0.8% silk protein hydrolysates fed groups compared with diabetic control group. Food and water intake were not different among diabetic and silk protein hydrolysates groups. In random state, the blood glucose levels in silk protein hydrolysates fed groups were lower than diabetic control group; however, the blood glucose in the three groups were not different in fasting state. Also silk protein hydrolysates improved the glucose tolerance in OLETF rat. The silk protein hydrolysates did not influence serum lipids while serum insulin and leptin levels were increased in the experimental OLETF rats. These results suggested that the administration of silk protein hydrolysates solution reduced significantly (p<0.05) an increasing rate of blood glucose level by stimulating the insulin secretion and increasing the serum leptin level.

• Journal of Food Hygiene and Safety
• /
• v.28 no.2
• /
• pp.152-157
• /
• 2013

We evaluated the anti-diabetic effects of Isaria tenuipes in diabetes mellitus type 2. For the experiments, the diabetic animal model OLETF rats were divided to 4 groups: Isaria tenuipes was administered mixed with the high fat diet 45% at dose levels of 0.0%, 0.1%, 1.0%, and 5.0% for 4 weeks. All animals have free access to water and high fat diet 45%. The diabetic clinical markers, including clinical signs, body weight and food intake, organ weights, blood glucose level, insulin level and HOMA-IR index, oral glucose tolerance test, GLUT4 mRNA and protein were measured at a time. After administration for 4 weeks, the blood glucose levels, insulin levels and HOMA-IR index of test groups were decreased compared with control group in dose-dependent manner. The body weight and diet consumptions were reduced in control group at 4 weeks. The treatments of Isaria tenuipes also showed high expression of GLUT4 mRNA and protein in the muscle of OLETF rats. The results suggest that Isaria tenuipes has anti-hyperglycemic effect attenuating blood glucose in the animal model of type 2 diabetes and might be useful as a functional diet for human diabetic diseases.

• Exercise Science
• /
• v.26 no.3
• /
• pp.204-211
• /
• 2017

PURPOSE: This study was to investigate the effects of resistance exercise on serum inflammatory markers and CatSper 1-4 expression in testis of OLETF rats. METHODS: Male OLETF rats were divided into two groups; control group (n=12), resistance exercise group (n=12). The exercise group performed a total of 8 weeks of moderate intensity resistance exercise on a 1.35 m vertical ladder with weights secured to their tails. RESULTS: The results of this study was following; The exercise group showed a significant decreased in the inflammatory ($IL-1{\beta}$, IL-6, $TNF-{\alpha}$) levels as compared to the control group. But CRP was no significant difference between control and exercise groups. Also, CatSper 1 and 2 were significantly increased in the exercise group compared to the control group, whereas CatSper 3, 4 were no significant difference between both groups. CONCLUSIONS: This study suggests that resistance exercise training can contribute to reduce pro-inflammatory responses in whole body and it affects male reproductive function by improve sperm quality and CatSper protein expression.

• BMB Reports
• /
• v.43 no.5
• /
• pp.337-343
• /
• 2010

Fenofibrate, an agonist of $PPAR{\alpha}$, plays an important role in activating many proteins catalyzing lipid metabolism, and it also has a considerable effect on improvement of insulin sensitivity in the diabetic condition. To investigate fenofibrate-dependent expression of peripheral tissue proteins in diabetes, we analyzed whole muscle or fat proteins of fenofibrate-fed OLETF rats, an animal model of type II diabetes, using 2-dimensional gel electrophoresis. We found that many proteins were specifically expressed in a fenofibrate-dependent manner in these diabetic rats. In particular, a functionally unknown C11orf59 protein was differentially expressed in the muscle tissues (about 5-fold increase) in fenofibrate-fed OLETF rats as compared to control rats. Additionally, the signal proteins phosphatidylethanolamine binding protein and IkB interacting protein were differentially regulated in the fenofibrate-treated adipose tissues. We suggest here that these proteins might be involved in controlling lipid or carbohydrate metabolism in diabetes via $PPAR{\alpha}$ activation.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2006.09a
• /
• pp.100.1-100.1
• /
• 2006

• Proceedings of the Korean Society of Life Science Conference
• /
• 2007.10a
• /
• pp.124.1-124.1
• /
• 2007

See Full Text