Effect of injected yeast glucan on the activity of macrophages in Atlantic salmon, Salmo salar L., as evaluated by in vitro hydrogen peroxide production and phagocytic capacity.

• Main Authors: Brattgjerd, S, Evensen, O, Lauve, A
• Format: Text
• Language: English
• Published: 1994
• Subjects: Research Article; Atlantic salmon; Salmo salar
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1414938; http://www.ncbi.nlm.nih.gov/pubmed/7835949

A prepared polysaccharide from the cell wall of yeast, M-Glucan, has previously been demonstrated to have immunostimulatory effects in salmonids as observed by enhanced in vivo non-specific disease resistance in Atlantic salmon, Salmo salar L., and increased in vitro bactericidal activity of rainbow trout, Oncorhynchus mykiss (Walbaum), macrophages. In the present study M-Glucan was injected intraperitoneally into Atlantic salmon and the effect on core components in the non-specific part of the immune system was observed. The hydrogen peroxide (H2O2) production of isolated head kidney macrophages from glucan-injected fish was measured 3 and 6 weeks after M-Glucan treatment and was increased at both time-points upon phorbol myristate acetate-(PMA) triggering. Without PMA triggering the difference was only significant 3 weeks after glucan injection when compared to a control group injected with saline. In a phagocytic assay with macrophages and Vibrio salmonicida the initial uptake of bacteria was elevated at both 3 and 6 weeks after glucan treatment. There was no significant difference when uptake of another fish pathogenic bacteria, Renibacterium salmoninarum, was studied. Treatment of Atlantic salmon with M-Glucan also resulted in enhanced serum lysozyme activity in week 3 of the experimental period. The results indicate that M-Glucan elevates the activity of the non-specific part of the immune system and the use of M-Glucan as an immunostimulant is discussed.