禁食与胰岛素处理对鳜血糖和leptin-A基因表达的影响(英文)

摘要

为研究硬骨鱼类leptin基因表达与血糖之间的关系, 研究在禁食与胰岛素处理后, 检测鳜血糖和肝脏、肠道和脂肪组织leptin-A基因表达水平.在禁食实验中, 鳜被禁食10d, 并分别于禁食后0、4h、2d、6d和 10d取样.禁食后6d鳜血糖开始降低, 禁食后10d鳜血糖显著降低.同时, 禁食后6d鳜肝脏leptin-A基因 mRNA表达水平显著升高, 禁食后4h鳜肠道和脂肪组织leptin-A基因mRNA表达水平均显著升高.在胰岛素处理实验中, 分别于注射后12h和36h取样.腹腔注射胰岛素后12h, 鳜血糖显著降低, 而鳜肝脏、肠道和脂肪组织leptin-A基因mRNA表达水平无明显变化.腹腔注射insulin后36h, 鳜肠道leptin-A基因mRNA表达水平显著升高.研究结果表明, 长期禁食或胰岛素处理均能够降低鳜血糖水平, 且影响消化器官和脂肪储存器官leptin-A基因表达.%Leptin has been reported to play important roles in regulation of glucose homeostasis in mammals. However, the relationship between blood glucose and leptin gene expression in teleosts is largely unknown. In the present study, blood glucose and leptin-A gene expression in liver, intestine and visceral adipose tissue were characterized in Chinese perch (Siniperca chuatsi) after fasting or insulin treatment. In the fasting experiment, Chinese perch were fasted for 10 days, sampling at 0, 4h, 2d, 6d and 10d after fasting. Blood glucose was significantly decreased at 10d after fasting; leptin-A mRNA expression was significantly increased in liver at 6d after fasting, and significantly increased in intestine and visceral adipose tissue at 4h after fasting. In the insulin treatment experiment, Chinese perch were intraperitoneally injected with bovine insulin (80 IU/kg body weight) or 0.7％ saline as control, sampling at 12h and 36h post treatment. Blood glucose decreased significantly at 12h after insulin treatment, and leptin-A mRNA expression in intestine increased significantly at 36h after insulin treatment, which suggesting that prolonged fasting and insulin treatment decreased blood glucose, and increased leptin-A gene expression in fat depot organ and digestive organ of fish.