Effects of large dosage of beta-carotene on anti viral immune function in Japanese parrotfish (Oplegnathus fasciatus)

取日本鹦鹉鱼（Oplegnathus fasciatus）脾脏淋巴细胞，与100mug/ml连接到Sepharose 4B珠上的豆豆蛋白A孵卵48h，收集刺激后的细胞上清液。巯基乙酸盐诱导的同种异体腹腔巨噬细胞（Pmphi）与或不受刺激的细胞上清液孵育。然后测定了Pmphi对灭活酵母的吞噬活性和过氧化物酶的产生。受刺激的细胞上清液增加了同种异体Pmphi的吞噬活性和过氧化物酶的产生。这些受刺激的细胞上清液在56ºC加热30min或在pH为2的缓冲液中透析24h后，活性完全丧失，类似于IFN_< γ >。受刺激的细胞上清液不增加异源小鼠Pmphi的吞噬活性和过氧化物酶的产生。上述结果提示，日本鹦嘴鱼脾脏淋巴细胞在体外可产生一种巨噬细胞激活因子，该因子可能为IFN_< γ >，并与Sepharose 4B珠结合。在接下来的试验中，日本鹦嘴鱼幼鱼饲喂β -胡萝卜素添加饲料（β -胡萝卜素添加轮虫和湿粒：5000杯/100g） 12个月。然后检测免疫功能。1) β -胡萝卜素添加组脾淋巴细胞产生的IFN_< γ >高于对照组。2) β -胡萝卜素添加组绵羊红细胞抗体产量高于对照组。3) β -胡萝卜素添加组Pmphi对灭活酵母菌的吞噬活性高于对照组。4)两组血清中Ht、Hb、蛋白值无显著差异。高剂量的β -胡萝卜素未观察到鱼患病和生长障碍。这些结果表明，在日本鹦嘴鱼养殖中添加β -胡萝卜素饲料可以生产出对传染病具有高抗性的鱼。

Spleen lymphocytes were prepared from Japanese parrotfish (Oplegnathus fasciatus) and incubated with 100mug/ml of Concanavalin A bound to Sepharose 4B beads for 48h, and then the stimulated cell supernatants were collected. Thyoglycolate induced, allogenic, peritoneal macrophages (Pmphi) were incubated with or without stimulated cell supernatants. Then, the phagocytic activity of Pmphi against inactivated yeast and peroxidase production were measured. Stimulated cell supernatants increased the phagocytic activity and the peroxidase production of allogenic Pmphi. The activities of these stimulated cell supernatants were lost completely when they were heated at 56ﾟC for 30min or dialyzed against a pH 2 buffer for 24h-similar to IFN_<gamma>. Stimulated cell supernatants did not increase phagocytic activity and peroxidase production of heterogenic mouse Pmphi.These finding suggest that the spleen lymphocytes of Japanese parrotfish can produce a macrophage activating factor in vitro with concanavalin A bound to Sepharose 4B beads, and that this factor may be IFN_<gamma>.In next experiment, Japanese parrotfish larvae were served the beta-carotene supplemented diets (BETA-carotene Plemented rotifer and moist-pellet : 5,000 mug/100g) for 12 months. Then, the immune function were examined.1) The spleen lymphocyte from beta-carotene supplemented group produced more IFN_<gamma> than control group.2) Antibody production for sheep red blood cell in BETA-carotene supplemented group were higher than control group.3) Phagocytic activity of Pmphi against inactivated yeast in beta-carotene supplemented group were were higher than contorol group.4) The Ht, Hb and serum protein value were not difference in both groups. Illness and growth obstruction of fish were not observed by the high dosage of beta-carotene.These finding suggest that the using of beta-carotene supplemented diets for aquaculture of Japanese parrotfish can produce high resistance fish for infectious disease.