On the use of dexamethasone to block the pituitary-interrenal axis in the brown trout, Salmo trutta L.
Oral administration of dexamethasone in a single meal at a dose of 3 micrograms g-1 body wt was sufficient to block the secretion of ACTH and cortisol in brown trout subjected to a handling stress followed by 30 min confinement. This dose, however, also had a marked effect on several of the circulating blood cell types. Lymphocyte and neutrophil counts were reduced in dexamethasone-treated fish whereas erythrocyte counts increased. The value of dexamethasone as a tool for investigating the role of interrenal tissue during stress responses in teleost fish is limited by its cortisol-like effects on other steroid-sensitive tissues.
D000311:Adrenal Glands / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology*; D004906:Erythrocyte Count; D004912:Erythrocytes / Q000187:drug effects; D006854:Hydrocortisone / Q000378:metabolism; D007401:Interrenal Gland / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D007958:Leukocyte Count; D008214:Lymphocytes / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D012487:Salmonidae / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology; D014337:Trout / Q000502:physiology*
D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone