The response of adipose tissues to oxidative stress by exercise : with special reference to the role of EC-SOD in splanchnic adioise tissue

点击翻译按钮获取中文摘要

The main findings obtained during 2005-2006 are as follows:1. The effect of acute exercise on β-adrenergic receptor (β-AR) trafficking was investigated in rat adipocytes. As the result, the mechanism underlying the increased density of β_2-AR up to at least 3 h after exercise might involve alterations in a multistep event involving the coordinate interaction among proteins mediating β_2-AR trafficking, in which both the receptor-agonist interactions and ubiquitin-proteasome pathway have a key role. However, the decreased protein expression of β_2-AR at 24 h might be due to some change occurring at the translational levels.2. The effect of exercise training on oxidative stress was investigated in rat adipocytes. In consequence, the level of thiobarbituric acid-reactive substances (TBARS) was significantly decreased in splanchnic adipose tissue, but not in peripheral adipose tissue. Meanwhile, extracellular superoxide dismutase (EC-SOD) level appeared to increase only in splanchnic adipo … More se tissue. Considering reduced level of monocyte chemoattractant protein-1 (MCP-1) in splanchnic adipose tissue after training, the findings obtained suggest that physical training reduces oxidative stress in splanchnic adipose tissue, resulting in improvement in lifestyle-related disease.3. The antioxidative effect of new lychee-derived polyphenol Oligonol converted into a low-molecular form (Amino Up Chemical Co., Ltd., Sapporo) was investigated in mouse adipocytes. Although the levels of splanchnic adipose tissue mass and TBARS in mice given a high fat diet (HFD) were significantly higher than those in control mice, Oligonol definitely inhibited such HFD-induced increases. Expression of TNF-α and MCP-1 genes in splanchnic adipose tissue of HFD mice was also significantly higher than that in control and HFD + Oligonol mice. Moreover, the expression of EC-SOD gene was enhanced only in splanchnic adipose tissue of HFD + Oligonol mice. These results suggest that Oligonol has favorable effects on oxidative stress. Less