THE ADRENOCORTICOTROPIC HORMONE STIMULATION TEST - ITS POTENTIAL USE AND LIMITATIONS IN RED DEER (CERVUS-ELAPHUS)

The adrenocorticotrophic hormone (ACTH) stimulation test was assessed in red deer (Cervus elaphus). Following injection (i.v.) of 0, 100, 25 0, or 500 mu g synthetic ACTH in farmed hinds (5 per group; mean live mass 78 kg), peak plasma cortisol concentrations occurred 30 min later . There was no dose effect on the peak levels attained, but the durati on of the response increased with dose. The response of wild hinds (me an live mass 64 kg) to 500 pg ACTH administered at the time of capture was studied. Plasma cortisol concentrations were high prior to ACTH a dministration (238 +/- 17.6 nmol/L; mean +/- SE). Eighty minutes later , although concentrations were lower overall, they were significantly higher in ACTH-treated than in control animals (21 per group). Twenty farmed male red deer calves (aged 5 months at the outset; mean live ma ss 44 kg) were permanently housed after weaning. One hundred microgram s of ACTH was injected at weeks 0 (just after weaning) and 12. At week 12 mean cortisol concentrations were lower both before and after ACTH injection, although ACTH significantly increased plasma cortisol conc entration on both occasions. Together these experiments suggest that t he ACTH stimulation test can be employed in some classes of red deer b ut that it is not appropriate when animals have a high initial plasma cortisol concentration.