Jin Junyan, Zhu Xiaoming, Han Dong, Yang Yunxia, Liu Haokun, Xie Shouqi
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, the Chinese Academy of Sciences, Wuhan, Hubei, China.
Gen Comp Endocrinol. 2017 May 15;246:363-371. doi: 10.1016/j.ygcen.2017.01.012. Epub 2017 Jan 6.
To test the hypothesis that response to insulin by regulating glucose and lipid metabolism in gibel carp A strain may be different from that in DT strain, bovine insulin was injected into both strains of gibel carp after previous fasting for 48h. The results showed that insulin induced hypoglycemia at 3h in 2 strains, and that this was coupled with increased expression of glucose transporters (GLUT2 in the liver and GLUT1, GLUT4 in the muscle) and glycolytic enzyme (HK2 in the muscle) in both strains. Insulin induced increased glycolysis (GK) and fatty acid oxidation (ACO3 in the liver and CPT1a, ACO3 in the muscle) in the DT strain. Conversely, very strong lipogenic capacity, as indicated by higher mRNA levels of transcription factor of fatty acid anabolism (SREBP1) and lipogenic enzymes (ACC, ACLY, and FAS) and decrease lipolytic capacity as indicated by lower mRNA levels of fatty acid oxidation enzymes in the liver (ACO3) and muscle (CPT1a and ACO3) detected in the A strain after insulin injection. Higher plasma insulin levels and decreased plasma free fatty acid levels were detected at 8h post insulin injection in A strain induced hypoglycemia. However, plasma glucose levels returned to baseline and no effect on fatty acid levels in the DT strain was observed in response to insulin treatment at the same point in time. These insulin-strain interactions demonstrated that insulin induced different changes in glucose and lipid metabolism in these 2 strains as expected.
为了验证银鲫A系和DT系对胰岛素调节葡萄糖和脂质代谢的反应可能不同这一假设，在预先禁食48小时后，将牛胰岛素注射到这两个品系的银鲫中。结果表明，胰岛素在3小时时使两个品系均出现低血糖，并且这与两个品系中葡萄糖转运蛋白（肝脏中的GLUT2以及肌肉中的GLUT1、GLUT4）和糖酵解酶（肌肉中的HK2）的表达增加有关。胰岛素在DT系中诱导糖酵解（GK）和脂肪酸氧化增加（肝脏中的ACO3以及肌肉中的CPT1a、ACO3）。相反，在A系中，胰岛素注射后检测到脂肪酸合成代谢转录因子（SREBP1）和脂肪生成酶（ACC、ACLY和FAS）的mRNA水平较高，表明其具有很强的脂肪生成能力，而肝脏（ACO3）和肌肉（CPT1a和ACO3）中脂肪酸氧化酶的mRNA水平较低，表明其脂肪分解能力下降。在A系中，胰岛素注射后8小时检测到较高的血浆胰岛素水平和降低的血浆游离脂肪酸水平，诱导了低血糖。然而，在同一时间点，DT系中血浆葡萄糖水平恢复到基线，并且未观察到胰岛素处理对脂肪酸水平有影响。这些胰岛素与品系之间的相互作用表明，胰岛素在这两个品系中诱导了如预期的葡萄糖和脂质代谢的不同变化。
