急冷与空气暴露联合胁迫对凡纳滨对虾生理代谢影响

【目的】探明无水保活流通过程中凡纳滨对虾(Litopenaeus vannamei)响应急冷(acute cold,AC)与空气暴露(waterless duration,WD)联合胁迫的生理代谢调节规律。【方法】研究模拟产业运输实际,分析联合胁迫(AC+WD)进程中凡纳滨对虾血液和肝胰腺典型生化指标,以及肝胰腺组织病理变化。【结果】AC胁迫后,凡纳滨对虾生理应激指标血清皮质醇含量由正常组(normal control,NC)的(326.90±4.61)pg/mL显著增加到AC组的(427.16±7.92)pg/mL(P<0.05),AC+WD组则随时间延长而逐渐降低。血清葡萄糖含量在联合胁迫6 h后达到最大值(26.31±1.05)mg/dL,乳酸在9 h达到峰值(7.90±0.11)mmol/L。AC及AC+WD组中血蓝蛋白、尿素氮和肌酐含量较NC组均发生不同程度的增加,而总蛋白含量先升后降,总胆固醇和甘油三酯含量呈胁迫时间依赖性下降。血清谷草转氨酶、谷丙转氨酶、酸性和碱性磷酸酶活力呈上升趋势,并在9 h达到峰值。以上生化指标在胁迫复苏组有所恢复,表明AC+WD双重胁迫引起凡纳滨对虾物质代谢紊乱,复苏后机体生理应激和代谢系统发生一系列代偿性调节,且胁迫进程中肝胰腺组织病理损伤特征进一步解释了凡纳滨对虾响应环境联合胁迫的结构基础。【结论】无水保活流通过程中双重胁迫时间依赖性改变凡纳滨对虾生理应激水平和物质代谢,在9 h时可明显造成肝胰腺组织结构损伤,进而影响机体存活。

Physiological Response and Metabolic Regulation of Litopenaeus vannamei Exposed to Combination Stress of Acute Cold Exposure and Chronic Waterless Duration

【Objective】To elucidate the physiological modulation mechanism of Litopenaeus.vannamei in response to a combination stress of acute cold exposure and chronic waterless duration during water-free transportation.【Methods】Based on the simulation of transport practice,the changing profiles of typical biochemical indicators in hemolymph and hepatopancreas tissues were determined,and the histopathology injury was characterized.【Results】The serum cortisol concentration significantly increased from the value of(326.90±4.61)pg/mL at AC group to(427.16±7.92)pg/mL at NC group(P<0.05),and the gradual decrease was observed at AC+WD groups.With the prolongation of combined stress of AC+WD,the glucose concentration reached the maximum of(26.31±1.05)mg/dL at 6 h in AC+WD group,while the maximum of lactic acid concentration(7.90±0.11)mmol/L was detected at 9 h(P<0.05).The concentrations of hemocyanin,urea nitrogen and creatinine in serum increased to some different degrees at AC and AC+WD groups.Although the concentration of total cholesterol and triglyceride decreased in a duration-dependent manner,the total protein concentration in serum elevated before 3 h and descend afterwards.The activities of aspartate aminotransferase,alanine aminotransferase,acid phosphatase and alkaline phosphatase in serum of shrimps elevated with the prolongation of combined stress and reached the maximum at 9 h.The above-detected at revived group exhibited regression towards the values at NC group.In addition,histopathological result suggested the impairment of hepatopancreas tissue during combined stress.Overall,these variations of biochemical indicators and histopathological impairment indicated that combined stress caused the disorder of substrate metabolism and induced the cytostructural degradation.【Conclusion】Combined stress altered the physiology and substrate metabolism of L.vannamei in a time dependent manner during waterless live transport and the obvious pathology injures in hepatopancreas tissue was observed,which consequently induced the mortality.