Jin Junyan, Yang Yunxia, Zhu Xiaoming, Han Dong, Liu Haokun, Xie Shouqi
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.
Gen Comp Endocrinol. 2018 Oct 1;267:18-28. doi: 10.1016/j.ygcen.2018.05.023. Epub 2018 May 23.
We compared the glucose clearance ability of gibel carp CAS III (A strain) with gibel carp Dongting (DT strain). A previous study suggested that these two strains responded to insulin differently. As insulin plays an important role in glucose utilization, we hypothesized that the ability to eliminate excess glucose after a glucose load would differ between A strain and DT strain. To test this hypothesis, fasted specimens of both strains of gibel carp were injected with glucose. As expected, glucose induced hyperglycemia in both A strain and DT strain. In both strains, mRNA levels of the glycolytic enzyme 6-phosphofructokinase (6PFK) increased in the white skeletal muscle 8 h post-injection, while expression levels of glucose-6-phosphatase (G6Pase), fructose 1,6-bisphosphatase (FBPase), and phosphoenolpyruvate carboxykinase (PEPCK) decreased in the liver 8 h post-injection. In the DT strain, both GLUT4 expression and muscular glycolytic processes increased, as reflected by elevated hexokinase 2 (HK2) and pyruvate kinase (PK) mRNA expression levels. The DT strain also returned to basal glycemia more quickly than the A strain (within 6 h versus more than 12 h). The glycogen concentration in the liver of the DT strain was higher than that of the A strain, indicating that the DT strain was better able to store glucose as glycogen than the A strain. Overall, the DT strain was better able to clear excess blood glucose after the glucose tolerance test than the A strain.
我们比较了银鲫CAS III（A品系）和洞庭银鲫（DT品系）的葡萄糖清除能力。先前的一项研究表明，这两个品系对胰岛素的反应不同。由于胰岛素在葡萄糖利用中起重要作用，我们推测A品系和DT品系在葡萄糖负荷后消除过量葡萄糖的能力会有所不同。为了验证这一假设，对两个品系的银鲫禁食标本注射葡萄糖。正如预期的那样，葡萄糖在A品系和DT品系中均诱发了高血糖。在两个品系中，注射后8小时，白色骨骼肌中糖酵解酶6-磷酸果糖激酶（6PFK）的mRNA水平均升高，而注射后8小时，肝脏中葡萄糖-6-磷酸酶（G6Pase）、果糖1,6-二磷酸酶（FBPase）和磷酸烯醇式丙酮酸羧激酶（PEPCK）的表达水平均下降。在DT品系中，葡萄糖转运蛋白4（GLUT4）的表达和肌肉糖酵解过程均增加，这通过己糖激酶2（HK2）和丙酮酸激酶（PK）mRNA表达水平的升高得以体现。DT品系也比A品系更快恢复到基础血糖水平（6小时内恢复，而A品系超过12小时）。DT品系肝脏中的糖原浓度高于A品系，这表明DT品系比A品系更能将葡萄糖储存为糖原。总体而言，在葡萄糖耐量试验后，DT品系比A品系更能清除过量的血糖。
