凡纳滨对虾不同组织内SOD、POD酶的细胞化学定位

运用电镜酶细胞化学技术对凡纳滨对虾(Litopenaeus vannamei)体内肝脏、肌肉、心脏、复眼和鳃等5种组织的SOD和POD酶的细胞化学定位进行了研究,并与感染病毒的凡纳滨对虾体内5种组织中SOD和POD的细胞化学定位进行比较。结果显示,在健康对虾体内,SOD酶阳性反应颗粒主要定位于肌肉、心脏、肝脏和鳃等组织细胞的线粒体膜、细胞质中,以及肝细胞的脂滴周围;POD酶主要定位于心脏、鳃和肝脏组织细胞的过氧化物酶体内,肝细胞中脂滴周围也有POD的阳性反应颗粒。感染病毒后,各组织细胞表现出明显的病理性结构变化,大量的髓样小体出现,脂滴数量明显减少。同时各组织中SOD和POD酶的细胞化学定位也发生了明显的变化,表现为心脏、鳃、肌肉组织细胞胞质中的SOD阳性颗粒消失,肝细胞中的SOD阳性颗粒明显减少,在心脏和鳃的线粒体基质内也出现SOD阳性颗粒;POD仍主要定位在过氧化物酶体中,但心脏中的过氧化物酶体解体而有许多呈阳性反应的小颗粒分布在细胞质中。结果表明SOD和POD在凡纳滨对虾防御氧的毒性损伤以及整个机体的免疫功能等方面起着重要的作用。  

CYTOCHEMICAL LOCATION OF SUPEROXIDE DISMUTASE AND PEROXIDASE IN DIFFERENT TISSUES OF LITOPENAEUS VANNAMEI

Superoxide dismutase (SOD) and peroxidase (POD) are two important anti- oxidation enzymes that exist widely in tissues of aerobic and anaerobic creatures. SOD and POD have been taken as two immune enzymes and a marker with several other related enzymes in evaluating crustacean animals' immune function. Litopenaeus vannamei is Chinese major raised aquatic shrimp, and Virus is a major reason for the spreading of epidemic Litopenaeus vannarnei diseases. To improve the own immunity of Litopenaeus vannamei and enhance its anti-virus function become the basic method of comprehensive prevention and cure. Therefore, people pay more and more attention to study the immunity factors of Litopenaeus vannamei and improve their anti-diseases ability effectively.The activities and location of superoxide dismutase (SOD) and peroxidase (POD) in the liver, muscle, heart, eye and gill of Litopenaeus vannamei were studied with enzyme cytochemical technique of electronic microscope, compared with the infected shrimp. The results showed that SOD positive reactions were mainly deposited in mitochondrium membrane and cytoplasm in the cells of the liver, muscle, heart and gill of the healthy shrimp. Furthermore, SOD activity was located around lipid droplet in liver. POD positive reactions were mainly deposited in specific organelle: peroxisome in the cells of the liver, heart and gill respectively. There were also POD positive granules around lipid droplet in liver. In the infected shrimp, the obviously histopathological changes were detected in five tissues, and more myelin figures appeared in the cell of each tissue and the number of the fat drops in liver cells sharply reduced. There were evident differences in tissues between diseased shrimp and healthy shrimp in the activities and location of SOD and POD. SOD positive granules in cytoplasm of the muscle, heart and gill of the infected shrimp disappeared; and the activities of SOD in liver decreased. At the same time, SOD positive reactions were also found in mitochondrial matrix of heart and gill. POD positive reactions were still found in peroxisome of the liver, heart and gill. But the number of peroxisome positive reactions in liver and gill got decreased; POD positive granules around lipid droplet in liver almost disappeared; part of peroxisomes in heart disintegrated and lots of positive-reacting granules scattered in cytoplasm.The results indicated that the activities and distribution of SOD and POD isozyme in Litopenaeus vannamei cells had clear tissue-specific, and SOD and POD played an important role in defense oxygen toxicity injury and the immune function of Litopenaeus vannamei. Our study will provide theoretical foundation for the application of immune technology in disease prevention and control in Litopenaeus vannamei in future.