Effects of high, low molecular weight chitosan on carbohydrate metabolism in streptozotocin-induced type 1 diabetic rats

• Main Authors: Yu-Han Chang, 張毓涵
• Other Authors: Meng-Tsan Chiang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/17080852857018973069

碩士 === 國立臺灣海洋大學 === 食品科學系 === 97 === This study was designed to investigate the effects of high and low molecular weight chitosan on carbohydrate metabolism in streptozotocin-induced type 1 diabetic rats. The experiments were separated into four groups: (1) normal rats with 5% cellulose, (2) type 1 diabetic rats with 5% cellulose, (3) type 1 diabetic rats with 5% high molecular weight chitosan, (4) type 1 diabetic rats with 5% low molecular weight chitosan. As the results, both high and low molecular weight chitosan groups were lower than type 1 diabetic group in liver weight. In addition, low molecular weight chitosan group was higher than type 1 diabetic group in adipose tissue quantity. In these plasma biological values, we found that both high and low molecular weight chitosan groups were significantly reduced blood glucose, insulin, HOMA-IR, and fructosamine in plasma. In plasma lipid concentration, high and low molecular weight chitosan groups reduced the plasma total cholesterol in type 1 diabetic rats, however, they were no significant difference on triglyceride concentration and free fatty acids. Furthermore, TNF-���nconcentration was no significant difference in each group. On the other hand, in plasma leptin content, both high and low molecular weight chitosan groups raised obviously, and low molecular weight chitosan group was the highest. PAI-1 which mainly participated into agglutination system, from our results showed that high and low molecular weight chitosan groups both decreased PAI-1 content in plasma. On the protein level, PEPCK which is the hepatic key enzyme in gluconeogenesis had an abvious decrease in low molecular weight chitosan group. AMPK maintain the energy homeostasis, and the experimental result showed the phosphorylation of AMPK raised significantly in both high low molecular weight chitosan groups. In addition, we found that phosphorylation of p38 MAPK was inhibited in high and low molecular weight chitosan groups. UCP2 which is a transporter on mitochondria inner membrane had no significance from the experimental result. We also found the hepatic glycogen was increased in high and low molecular weight chitosan groups. In skeletal muscle, we knew the results from these experiments, akt and GLUT4 expression were elevated obviously in high and low molecular weight chitosan groups. Together, our results from present study suggest that chitosan may improve glucose uptake in peripheral tissues, thus decreasing plasma glucose.