肥胖幼鼠脂肪组织vaspin与胰岛素敏感性的关系

Correlation between vaspin concentration and insulin sensitivity in the visceral adipose tissue of young obese rats

摘要:

目的：探讨幼年肥胖Sprague-Dawlely（SD）大鼠脂肪组织vaspin含量与胰岛素敏感性的关系。方法：断乳3周SD大鼠24只，随机分为高脂饮食组和普通饮食组，每组12只。成功建模后，测定各组体重、腹围。禁食12 h 后取内眦静脉血测定空腹血糖（FPG）、空腹胰岛素（FINS）；再腹腔注射50%葡萄糖（2 g/kg），于注射后60 min、120 min再次取内眦静脉血测定各时间点血糖（BG）及胰岛素（INS）。幼鼠处死后将内脏脂肪组织称重。酶联免疫吸附法测定各组幼鼠内脏脂肪组织中vaspin的含量，并对vaspin表达量与各体格测量指标及胰岛素敏感性评价指标进行相关性分析。结果：高脂饮食组大鼠的体重、腹围、内脏脂肪重量、FPG、FINS、120 min INS、vaspin、胰岛素抵抗指数（HOMA-IR）、胰岛素分泌指数（HOMA-β）均高于普通饮食组（P<0.05），高脂饮食组胰岛素敏感指数（ISI）明显低于普通饮食组（P<0.01）。Vaspin含量与肝脏重量、内脏脂肪重量、腹围、120 min INS、FPG、FINS、HOMA-IR、HOMA-β呈正相关（P<0.05），而与ISI呈负相关（P<0.05）。结论：幼年肥胖SD大鼠胰岛素抵抗状态与vaspin高水平表达有关，推测vaspin是一种增加胰岛素敏感性、促进胰岛β细胞分泌胰岛素和改善糖耐量的脂肪细胞因子，可能参与了胰岛素抵抗、糖代谢紊乱状态的形成。

Abstract:

OBJECTIVE: To investigate the correlation between visceral adipose tissue-derived serine protease inhibitor (vaspin) concentration and insulin sensitivity in the visceral adipose tissue of young obese Sprague-Dawley (SD) rats. METHODS: Twenty-four SD rats which had been weaned 3 weeks before were randomly divided into two groups (n=12 each) to receive a high-fat and normal diet. The weight and abdominal circumference (AC) of each rat were measured, the fasting plasma glucose (FPG) and fasting insulin (FINS) in blood from the angular vein were measured after 12 hours of fasting and blood glucose (BG) and insulin (INS) levels in blood from the angular vein were measured at 60 and 120 minutes after intraperitoneal injection of 50% glucose (2 g/kg). The rats were sacrificed, and their liver and visceral adipose tissue were weighed. The vaspin concentration of the visceral adipose tissue in each rat was measured using ELISA. Correlation analysis was performed on the vaspin concentration and other indices. RESULTS: Compared with the normal diet group, the high-fat diet group showed significantly higher weight, AC, weight of visceral adipose tissue, FPG, FINS, 120 minute INS level, vaspin concentration, homeostasis model assessment for insulin resistance (HOMA-IR) and homeostasis model assessment of β cell function (HOMA-β) (P<0.05) Insulin sensitivity index (ISI) was significantly lower (P<0.01). Vaspin concentration was positively correlated with visceral adipose tissue and liver weight, AC, 120 minute INS level, FPG, FINS, HOMA-IR and HOMA-β (P<0.05), and negatively correlated with ISI (P<0.05). CONCLUSIONS: High expression of vaspin is associated with insulin resistance in young obese SD rats. Vaspin is presumably an adipocytokine that can increase insulin sensitivity, promote insulin secretion by islet β-cells and improve glucose tolerance, and it may be involved in insulin resistance and the disturbance of carbohydrate metabolism.