Summary
Plasma ACTH and corticosterone (B) concentration, ACTH content in the anterior pituitary
gland and B content in the adrenals were measured in intact, gonadectomised and testosterone
or estradiol replaced rats.
Plasma ACTH and B levels and adrenal B content were higher in female than male rats.
Neither orchiectomy nor testosterone replacement had an effect on plasma ACTH and
B concentration. Orchiectomy did not affect adrenal B content and decreased pituitary
ACTH while testosterone significantly lowered ACTH and B content in studied glands.
On the other hand ovariectomy did not change pituitary ACTH and adrenal B content
and notably lowered concentrations of these hormones in the blood. Estradiol replacement
resulted in an increase in plasma ACTH and B concentrations, an effect accompanied
by a marked drop in pituitary ACTH and an increase in adrenal B.
These findings indicate the distinct sex differences in basal plasma ACTH and B concentrations
with higher values in female rats, an effect dependent on the stimulatory action of
estradiol on pituitary-adrenocortical axis.
Key words
Rat - Gonadectomy - Gonadal Hormones - Adrenal Cortex - Anterior Pituitary - ACTH
- Corticosterone
