中华绒螯蟹肝胰腺白化症组织病理变化

The histopathological changes in tissues of Eriocheir sinensis with hepatopancreas albinism

采用常规石蜡切片技术和透射电镜技术,对患有肝胰腺白化症的中华绒螯蟹病变组织和细胞进行观察。发现病蟹肝胰腺、鳃、肌肉等组织细胞发生了不同程度的病变,其病理特征为肝细胞水肿、变性、坏死,细胞中脂肪颗粒锐减,线粒体水肿、嵴消失、形成空泡,内质网、溶酶体解体成小泡。鳃组织增厚,上皮细胞微绒毛排列疏松、不规则,部分线粒体嵴消失,出现膜性退化。坏死的肝细胞和鳃上皮细胞中出现细菌颗粒。肌细胞的病变主要表现为细胞核固缩,肌丝松驰、水肿、断裂、肌质网溶解形成小泡。中华绒螯蟹具有重要生理功能的肝胰腺、鳃组织发生了严重病变,使其功能损伤,不耐运输;而肌肉的松驰、肝胰腺脂肪的锐减影响了中华绒螯蟹的品质。同时,病变组织和细胞中未见病毒等生物病原,表明该病为非生物性疾病。

＂ Hepatopancreas albinism＂ is one of the most serious diseases of Eriocheir sinensis. Observations on the lesions in tissues and cells of Eriocheir sinensis with hepatopancreas albinism were carried out by using the routine paraffin section preparation method and by a high-resolution transmission electron microscope technique. The structural changes in varying degrees were observed in the hepatopancreas, gills, and muscles of diseased crabs. The pathological characteristics mainly appeared as follows： firstly, liver cells showed swelling, degeneration, and even necrosis, within which the fatty granules greatly decreased, the swollen mitochondria lost their cristae and formed vacuoles, and the endoplasmic reticulum and lysosome degraded into vesicles. Secondly, the gills appeared to be expanded, and the microvilli arranged sparsely and abnormally in gill epithelial cells. Some mitochondria cristae disappeared, and regressed into membranous structures. Also, bacteria particles could be found in the necrotic gill epithelial cells and liver cells. Thirdly, in the muscle cells, nuclei showed pyknosis, muscular fibers appeared to be relaxed, swollen, and split, and sarcoplasmic reticulum disaggregated into vesicles. It suggested that severe structural changes in hepatopancreas, gills, and muscles impaired the physiological functions of crabs, thereby crabs with hepatopancreas albinism could not resist long-distance transportation. In addition, the relaxation of muscles and the dramatic reduction in fat content of hepatopancreas caused poor quality of commercial crabs. Ultrastructural observations showed that no virus and other biological agents were found in tissues or cells of diseased crabs, which indicated that hepatopancreas albinism was caused by non-living agents.