ACCUMULATION OF IMMUNOMODULATORY LAMINARAN [BETA(1,3)-D-GLUCAN] IN THE SPLEEN AND KIDNEY OF ATLANTIC SALMON, SALMO-SALAR L

The tissue distribution of H-3- and FITC-laminaran in Atlantic salmon, Salmo salar L., was investigated after intravenous administration. Li quid scintillation counting and whole-body autoradiography revealed th at the concentration of H-3-labelled laminaran in the spleen and anter ior kidney was higher than in blood throughout the experimental period (1 h to 12 days). Renal excretion and intestinal exsorption were the main elimination pathways for laminaran. Microscopic examination revea led accumulation of FITC-labelled laminaran in macrophages in kidney a nd spleen. In addition, endothelial cells in the kidney, spleen, liver and intestine contained the immunomodulator. Thus, these experiments show that laminaran accumulates and is retained in immunologically rel evant cells in the kidney and spleen.