饥饿胁迫对日本蟳抗氧化酶活性和细胞超微结构的影响

采用透射电镜技术和分光光度法研究了饥饿胁迫对日本蟳(Charybdis japonica)鳃、肝胰腺、心脏和肌肉组织超氧化物歧化酶(SOD)、过氧化氢酶(CAT)及其超微结构的影响. 抗氧化酶研究结果表明: 日本蟳体内SOD和CAT的活性显示出高度的组织特异性, SOD活性在组织间分布大小顺序为心脏>鳃>肌肉>肝胰腺, CAT大小顺序为肝胰腺>心脏>鳃>肌肉. 两种酶在饥饿胁迫下发生了相应的变化, 16d内SOD整体表现出刺激作用, 鳃中CAT呈现明显的抑制作用, 肝胰腺中CAT活性先降后增. 细胞超微结构观察显示: 饥饿胁迫下日本蟳4种组织细胞的超微结构都有不同程度的变化. 鳃细胞的损害表现为鳃丝水肿、角质层变薄、线粒体部分溶解; 肝胰脏细胞的主要损害特征为肝管微绒毛减少、部分线粒体解体、内质网扩张以及少量细胞核不规则; 心脏细胞中部分线粒体溶解、肌原纤维肿胀; 肌肉细胞部分细胞核染色质固缩. 由此可见, 日本蟳机体本身对饥饿胁迫具有有限的防御能力.

Effects of starvation stress on the activities of antioxidant enzymes and cell ultrastructure of Charybdis japonica

Using the transmission electron microscopy and spectrophotometry, the current study was designed to investigate the effect of the starvation stress on the activities of superoxide dismutase (SOD), catalase (CAT) and the ultrastructure of 4 tissues (gill, hepatopancreas, heart and muscle) in Charybdis japonica. The results indicated that SOD and CAT activities in Charybdis japonica exhibited high tissue specificity. The order of SOD activity distributed in different tissues from high to low was heart, gill, muscle and hepatopancreas. The order of CAT activity was hepatopancreas, heart, gill and muscle. SOD and CAT activities have been changed , following the introduction of the starvation stress. SOD holistically showed a significant stimulating effect within 16 days. CAT in gill was alleviated and CAT in hepatopancreas showed initial decrease and subsequent increase. The ultrastructure of four tissue cells were significantly altered under the starvation stress. Swelling gill filament, thinning cuticle and partially dissolved mitochondria was evident in Gill cells. Decreased microvilli, mitochondrion partly disintegrated, expanded endoplasmic reticulum and a few irregular nuclei was found in hepatopancreas cells. Mitochondria in heart cells was partially dissolved and myofibrils were swelled. Chromatin of muscle cells were pagans. It is concluded that Charybdis japonica itself has limited defense ability against starvation stress.