Different sensitivity of carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) to the immunomodulatory effects of UVB irradiation.
In order to study the sensitivity of two fish species, carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss), to the immunomodulatory effects of ultraviolet B (UVB) radiation, the fish were exposed to a single UVB dose of 50, 250, 500 or 1,000 mJ cm(-2). These species represent different phylogenetic groups of fish, and they differ also in their behaviour inhabitating often dark and turbid (carp) or clear and transparent waters (salmonids). Immune responses were studied on day 1 post-irradiation. Unexposed fish, and fish exposed to radiation depleted of UV wavelengths served as controls. UVB irradiation markedly enhanced the blood respiratory burst and cytotoxic activity in carp, but in the head kidney these parameters were significantly suppressed. Rainbow trout respiratory burst was affected only after exposure with the highest dose of UVB. Lymphopenia and granulophilia were noted in both fish blood after exposure. This study indicates that UVB irradiation modulates immune functions in both fish species studied, and that rainbow trout is more tolerant than carp against UVB. Fish are clearly adapted to the environmental UVB levels prevailing in their usual living habitats, but are also a target of undesired effects of UVB on immune functions whenever exposed to increased radiation levels.
Markkula
S Eveliina
SE
Department of Biological and Environmental Science, University of Jyväskylä, PO Box 35, Survontie 9 YAC, FIN-40014 Jyväskylä, Finland. eveliina.markkula@hus.fi
Salo
Harri M
HM
Rikalainen
Anna-Kaisa
AK
Jokinen
E Ilmari
EI
D000818:Animals; D002347:Carps / Q000276:immunology*; D003601:Cytotoxicity Tests, Immunologic / Q000662:veterinary; D004307:Dose-Response Relationship, Radiation; D006854:Hydrocortisone / Q000097:blood; D007107:Immune System / Q000528:radiation effects*; D007075:Immunoglobulin M / Q000097:blood; D007668:Kidney / Q000528:radiation effects; D007962:Leukocytes / Q000276:immunology / Q000528:radiation effects; D008163:Luminescent Measurements / Q000662:veterinary; D017686:Oncorhynchus mykiss / Q000276:immunology*; D016897:Respiratory Burst / Q000528:radiation effects; D013056:Spectrophotometry, Ultraviolet / Q000662:veterinary; D014466:Ultraviolet Rays
D007075:Immunoglobulin M; D006854:Hydrocortisone