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

用100µg/ml刀豆蛋白A与Sepharose4B结合的小球孵育48小时，收集刺激细胞上清液。将胸腺乙醇酸诱导的同种异体腹膜巨噬细胞(Pmphi)与或不与刺激细胞上清液共同孵育。然后，测定Pmphi对灭活酵母的吞噬活性和过氧化物酶的产生。刺激细胞上清液可增加同种异体Pmphi的吞噬活性和过氧化物酶的产生。当这些刺激细胞上清液在56ﾟ℃加热30min或在pH 2缓冲液中透析24小时时，其活性完全丧失。刺激细胞上清液不能增加异种小鼠脾淋巴细胞的吞噬活性和过氧化物酶的产生。这一结果表明，日本鹦鹉鱼的脾淋巴细胞能在体外产生一种巨噬细胞激活因子，这种因子可能是干扰素。在下一次实验中，日本鹦鹉仔鱼在饲料中添加β-胡萝卜素(添加β-胡萝卜素的轮虫和湿球：5,000µg/100g)，为期12个月。测定免疫功能：1)添加β-胡萝卜素组小鼠脾淋巴细胞产生的干扰素高于对照组；2)添加β-胡萝卜素组绵羊红细胞产生的抗体高于对照组；3)添加β-胡萝卜素组的Pmphi对灭活酵母的吞噬活性高于对照组。4)添加β-胡萝卜素组和对照组的Ht、Hb和血清蛋白水平无差异。高剂量的β-胡萝卜素没有观察到鱼的发病和生长受阻现象，说明在日本鹦鹉鱼养殖中添加β-胡萝卜素的饲料可以生产出对传染病具有高抵抗力的鱼。

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.