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牙鲆是海水养殖肉食性鱼类。本研究以灌喂葡萄糖的方式,研究糖胁迫对牙鲆(初始体重225±50g)肝脏蛋白质和脂肪代谢酶和消化酶活性的影响,为解析肉食性鱼类糖耐受能力弱的机制提供基础数据。共设计2个实验组,第1组为糖胁迫组,将葡萄糖溶液(500mg/ml)按照1.67g葡萄糖/kg体重的剂量灌喂给牙鲆;第2组为对照组,按第1组同等剂量灌喂牙鲆磷酸缓冲盐溶液(PBS,0.01mol/L)。分别在灌喂前(0h),灌喂后1、3、5、7、12、24和48h取样。结果表明,肝脏谷丙转氨酶活性在灌喂葡萄糖后表现出先下降后升高的趋势,在7h达到最低且显著低于灌喂前水平(P<0.05),谷草转氨酶活性与0h差异不显著(P>0.05)。葡萄糖-6-磷酸脱氢酶活性先升高后下降,在7h显著高于灌喂前水平(P<0.05)。脂蛋白脂酶、肝脂酶活性变化不显著(P>0.05)。肠道脂肪酶和胰蛋白酶活性先升高后下降,分别在5h和7h达到最高且显著高于灌喂前水平(P<0.05)。肠道淀粉酶和胃蛋白酶活性没有显著变化(P>0.05)。在对照组中,上述酶活性在不同取样时间点之间没有显著差异(P>0.05)。总的来说,糖胁迫影响了牙鲆肝脏的转氨酶活性,在一定程度上减弱了肝脏的氨基酸代谢强度,促进了肝脏脂肪酸的合成,增强了脂肪酶和胰蛋白酶的活性。
Flounder is a marine carnivorous fish. In this study, the effect of glucose stress on the activities of hepatic protein and lipid metabolism enzymes and digestive enzymes in flounder (initial body weight of 225 ± 50g) was studied by means of glucose instillation, which provided a basis for analyzing the weak mechanism of glucose tolerance in carnivorous fish data. A total of two experimental groups were designed. The first group was glucose stress group. Glucose solution (500mg / ml) was given to flounder according to the dosage of 1.67g glucose / kg body weight. The second group was the control group, Dose feeding flounder phosphate buffered saline (PBS, 0.01mol / L). The samples were taken before (0h), 1, 3, 5, 7, 12, 24 and 48h after inoculation. The results showed that alanine aminotransferase activity of liver decreased firstly and then increased after dripping glucose, reaching the lowest at 7h and significantly lower than that before feeding (P <0.05), while the activity of aspartate aminotransferase was not significantly different from 0h > 0.05). Glucose-6-phosphate dehydrogenase activity increased first and then decreased, and was significantly higher at 7h than before irrigation (P <0.05). Lipoprotein lipase, hepatic lipase activity did not change significantly (P> 0.05). Intestinal lipase and trypsin activity increased first and then decreased, reaching the highest at 5h and 7h and significantly higher than that before feeding (P <0.05). Intestinal amylase and pepsin activity did not change significantly (P> 0.05). In the control group, there was no significant difference in enzyme activity between different sampling time points (P> 0.05). In general, glucose stress affected the activity of transaminase in the liver of Japanese flounder, which attenuated the liver’s amino acid metabolism to a certain extent, promoted the synthesis of fatty acids in the liver, and enhanced the activity of lipase and trypsin.