The adrenal gland as a source of progesterone in red deer (Cervus elaphus) : A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science with Honours in the University of Canterbury

Abstract

The extra-ovarian contribution to peripheral plasma progesterone levels was assessed in five classes (n =4) of red deer ( Cervus elaphus ). Male and female weaner deer, mature hinds in seasonal anoestrous , hinds in the follicular stage of oestrous and ovariectomised deer recorded 4 nmol/I to 10 nmol/I elevations in plasma progesterone levels within 30 minutes of an ACTH analogue injection. Weaner hind responses to ACTH were higher (P < 0.02) than the other classes, whereas the weaner stags recorded longer plasma progesterone elevations (P < 0.05). Stress related responses occurred before the ACTH challenge resulting in elevations of progesterone and cortisol (P < 0.05 in ovariectomised deer) which appeared not to return to basal levels by ACTH administration. Plasma cortisol levels were elevated by 1.7 to 2.6 fold within 40 minutes of the ACTH injection to peak at concentrations of 104 nmol /I to 160 nmol /I. These data strongly implicate the adrenal gland in red deer as a significant source of progesterone which may be stimulated by acute stress. Further research. however, is needed in prepubertal red deer to understand the contribution of the adrenal gland to this stage of development.