亚硝态氮慢性胁迫对凡纳滨对虾体成分和糖代谢的影响

Effects of Chronic Nitrite Stress on Body Composition and Glucose Metabolism of Litopenaeus vannamei

中文关键词: 凡纳滨对虾  亚硝态氮胁迫  体成分  糖代谢

英文关键词: Litopenaeus vannamei  Nitrite stress  Body composition  Glucose metabolism

中文摘要:

      为研究亚硝态氮(NO2–-N)慢性胁迫对凡纳滨对虾(Litopenaeus vannamei)[(2.03±0.33) g]生长、摄食、体成分和糖代谢的影响，实验设置0 (对照组)、8 (N8组)、15 (N15组)和30 mg/L (N30组) NO2–-N浓度组，进行36 d的NO2–-N慢性胁迫实验。结果显示，随着NO2–-N浓度升高，对虾的终末体重、特定生长率、增重率和日摄食率均呈显著下降趋势。N8组和N15组对虾的血糖和肝胰腺中糖原含量在实验中期高于对照组，但最终均低于对照组，而肌肉中糖原含量在实验期间始终低于对照组。胁迫组凡纳滨对虾肌肉中的己糖激酶活力低于对照组；而肝胰腺己糖激酶活力和丙酮酸激酶活力均高于对照组，同时，肝胰腺乳酸含量与乳酸脱氢酶活力呈先上升后下降的趋势，最终与对照组相比无显著差异。终末体成分中，N30组的粗脂肪含量显著低于对照组。结果表明，NO2–-N慢性胁迫会降低对虾食欲，减缓凡纳滨对虾的生长，机体糖代谢调节可作为对虾应对NO2–-N慢性胁迫的短期响应，对虾对脂质的利用在应对NO2–-N慢性胁迫过程中起重要作用。

英文摘要:

      In this study, we examined the effects of chronic nitrite stress on the growth, feeding, body composition, and glucose metabolism of Litopenaeus vannamei [(2.03±0.33) g]. The experiment lasted for 36 days, and there were control group, N8, N15, and N30 (stress groups) with concentrations of 0, 8, 15, and 30 mg/L NO2–-N. With increasing NO2–-N concentrations, the final body weight, specific growth rate, weight gain rate, and feeding rate of the shrimp showed a significant decline. At day 18, the blood glucose and glycogen in the hepatopancreas in the N8 and N15 groups were higher than those in the control group; however, they were lower than the control group by the end of the experiment. The muscle glycogen in the stress group was always lower than the control group during the experiment. In addition, the activity of hexokinase in the muscle of the stress group was lower than that of the control group, whereas the activity of hexokinase and pyruvate kinase in the hepatopancreas of the stress group was significantly higher than that of the control group. Further, the activity of lactate dehydrogenase in the hepatopancreas first increased and then decreased, but there was no significant difference compared with the control group. In the final body composition, there was almost no change in the water and crude protein of each group, but the crude lipid content of the N30 group was significantly lower than that of the control group. The above results indicated that chronic stress of nitrite can reduce the appetite and slow down the growth in shrimps. The glucose metabolism in shrimp is only a short-term response model to cope with the chronic stress of nitrite. At the same time, according to the change of crude lipid, it is speculated that the lipid metabolism of L. vannamei played an important role in the chronic nitrite stress for the shrimps.