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

1996 Fiscal Year Final Research Report Summary

• Project/Area Number: 06660244
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: General fisheries
• Research Institution: Nagasaki University
• Principal Investigator: TACHIBANA Katsuyasu Nagasaki University Faculty of Fisheries Associate Professor, 水産学部, 助教授 (20171712)
• Co-Investigator(Kenkyū-buntansha): HARA Kenji Nagasaki University Faculty of Fisheries Associate Professor, 水産学部, 助教授 (10039737) ; ISHIHARA Tadashi Nagasaki University Faculty of Fisheries Professor, 水産学部, 教授 (40039722) ; TSUCHIMOTO Mutsuyosi Nagasaki University Faculty of Fisheries Professor, 水産学部, 教授 (20080525)
• Project Period (FY): 1994 – 1995
• Keywords: beta-carotene / Japanese parrotfish / IFN_<gamma>. / macrophages / lymphocytes

Research Abstract

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.