Vol. 87, Issue 1, 183-188, July 1999
Dexamethasone in resting and exercising men. II. Effects on
adrenocortical hormones
G.
Lac1,
P.
Marquet2,
A. P.
Chassain3, and
F. X.
Galen4
1 Department of Sports
Sciences, University of Clermont-Ferrand, 63172 Aubière Cedex;
2 Department of Pharmacology and
Toxicology, University Hospital, 87042 Limoges Cedex; and
3 Department of Medical Physiology
and Sports Medicine and
4 Department of Pharmaceutical
Physiology, University of Limoges, 87025 Limoges, France
This study presents the reactions of
adrenocorticosteroids (cortisol and aldosterone) and sex steroids
[testosterone, androstenedione, and dehydroepiandrosterone and
its sulfate (DHAS)] 1) to a
dexamethasone (Dex) treatment, which is expected to lower steroid
levels via the ACTH blockade, and 2)
to an exercise bout at maximal O2
consumption, which is expected to increase steroid production via ACTH
stimulation. Consistent with the decrease in ACTH, all steroids except
testosterone reacted negatively to Dex, independently of the dose (0.5 and 1.5 mg administered twice daily for 4.5 days). After exercise, plasma ACTH rose to 600% of basal value, resulting in a significant increase in aldosterone and adrenal androgens, but cortisol and DHAS
were unaffected. This apparently surprising result can be explained by
differences in peripheral metabolism: a theoretical calculation
predicted that after 15 min the increase in hormone concentration may
only reach 12% for cortisol and 2% for DHAS. For cortisol and adrenal
androgens, assays were carried out using plasma and saliva. The
consistent results obtained from the two matrices allow us to consider
salivary assays as a useful tool for steroid abuse detection.
dexamethasone suppression test; exercise; adrenal androgens; cortisol; saliva
