Adrenocortical suppression in the dog given a single intramuscular dose of prednisone or triamcinolone acetonide.
Adrenocortical function was assessed in dogs given a single intramuscular dose of either prednisone or triamcinolone acetonide (TCA; or saline solution to controls) to determine the duration of adrenocortical suppression caused by 2 commonly used glucocorticoids. The glucocorticoids were administered at recommended therapeutic doses; therefore, dogs given prednisone received a greater amount of glucocorticoid activity than did in dogs given TCA. Basal and ACTH-stimulated plasma cortisol concentrations, as determined by radioimmunoassay, were obtained once a week. Total intravascular eosinophil concentration and skin responses to intradermally injected histamine phosphate were quantitated. Dogs given TCA showed suppressed basal and ACTH-stimulated plasma cortisol concentrations 1 week after injection; the latter change persisted 2 weeks after injection. Adrenocortical function in 1 of 4 dogs given TCA remained suppressed for 4 weeks. In contrast, prednisone did not significantly alter adrenocortical function. Although intravascular eosinophil concentrations did not vary among groups, skin responses to intradermally injected histamine phosphate were reduced 6 days after prednisone and TCA were given.
D000302:Adrenal Cortex / Q000187:drug effects* / Q000502:physiology; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D003864:Depression, Chemical; D004285:Dogs / Q000502:physiology*; D004804:Eosinophils / Q000166:cytology; D005260:Female; D006632:Histamine / Q000031:analogs & derivatives / Q000494:pharmacology; D006854:Hydrocortisone / Q000097:blood; D007273:Injections, Intramuscular; D008297:Male; D011241:Prednisone / Q000008:administration & dosage / Q000494:pharmacology*; D011863:Radioimmunoassay / Q000662:veterinary; D012867:Skin / Q000187:drug effects; D014222:Triamcinolone Acetonide / Q000008:administration & dosage / Q000494:pharmacology*
D006632:Histamine; D000324:Adrenocorticotropic Hormone; D014222:Triamcinolone Acetonide; C027556:histamine phosphate; D011241:Prednisone; D006854:Hydrocortisone