Cortisol levels in red deer (Cervus elaphus) and fallow deer (Dama dama) after an acute ACTH administration

Abstract

Cortisol levels were determined in seven 2.5-year-old male red deer (Cervus elaphus) and 8 yearling male fallow deer (Dama dama) after an acute intramuscular injection of 0, 10, or 40 international units (IU) of ACTH, administered in June, July, or August. In both species a highly significant increase in cortisol concentration was observed within the first hour after both doses of ACTH. At the end of the rapid cortisol elevation (60 min post ACTH) the response in both species was equal for the 10 and 40 IU doses. Average pretreatment levels were around 1–2 μg/100 mL; peak levels registered in red deer were around 10 μg/100 mL, and in fallow deer maximal concentrations reached around 8 μg/100 mL. Although all deer responded to ACTH, strong interindividual differences in intensity of cortisol elevation were detected. The extent of increase of blood cortisol levels in response to ACTH appears to be an evolutionary adaptation of various cervid species to their respective environmental conditions.