Pathophysiological meaning of substances concerning defense mechanisms in fish skin

人工感染嗜水气单胞菌提高胡子鲶皮肤粘液中凝集素的活性。免疫鱼中未发生这种升高。使用针对兔凝集红细胞产生的抗体进行蛋白质印迹分析，发现皮肤凝集素由几种低分子量蛋白质组成。在卵中也发现了具有相同抗原性的凝集素，但由于其分子稳定性极低，纯化试验未能成功。接种弧菌的鲶鱼血浆中抗体滴度升高，而皮肤粘液滴度没有变化。这表明皮肤免疫系统对内部免疫系统的依赖性。另一方面，虹鳟鱼的皮肤免疫系统与体液免疫系统之间存在一定的联系;在产卵季节，皮肤表面真菌病感染较晚的鱼，其血浆免疫球蛋白浓度在产卵季节前高于未感染的鱼，中性粒细胞的吞噬活性和淋巴细胞对兔红细胞的玫瑰花结形成活性，皮肤粘液对红细胞的处理没有增强。这种实验可能需要纯化Jectin。此外，应考虑皮肤粘液中包含的其他因素的参与，以了解这些实验的结果，因为纤维物质被凝集在凝集的红细胞团中。

Lectin activity in the skin mucus of the catfish Clarias batrachus elevated by artificial infection with Aeromonas hydrophila. This raise did not occur in the immunized fish. Skin lectin was found to be composed of several lower molecular weight proteins, by western blotting analysis using antibody raised against agglutinated red blood cells in rabbit. Lectin showing the same antigenicity was also found in eggs.Trials to purify these lectins were not succeeded, because of extremely low stability of the molecules.Antibody titer of the blood plasma elevated in the vibrio vaccinated catfish, while the titer of the skin mucus showed no change. This suggest the dependency of the skin immune system from the inner one. On the other hand, relationship between the immune systems of the skin and body fluid was found in rainbow trout ; plasma immunoglobulin concentration had been higher during the pre-spawning season in fish infected later with fungal deseases on skin surface at the spawning season, than in non-infectes ones.Phagocytotic activity of the neutrophils and rosette forming activity of the lymphocytes against rabbit red blood cells, were not enhanced by the tretment of the skin mucus to the red blood cells. Purification of the Jectin might be needed for such experiment. In addition, participation of other factors included in the skin mucus should be considered to understand the results of these experiments, since fibrous substances were recoginzed in the mass of agglutinated red blood cells.