Download PDF
Horm Metab Res 1973; 5(4): 289-292
DOI: 10.1055/s-0028-1093930
Originals

© Georg Thieme Verlag KG Stuttgart · New York

Reduced Plasma Thyrotropin Response to Thyrotropin Releasing Hormone After Dexamethasone Administration in Normal Subjects

G.  Faglia , C.  Ferrari , P.  Beck-Peccoz , A.  Spada , P.  Travaglini , B.  Ambrosi
  • 2nd Medical Clinic, Endocrine Unit, University of Milan, Milan, Italy
Further Information

Publication History

Publication Date:
07 January 2009 (online)

Also available at
  PDF Download  Permissions and Reprints

Abstract

In order to elucidate at which level glucocorticoids act in inhibiting thyrotropin (HTSH) secretion in man, 200µgm of synthetic thyrotropin releasing hormone (TRH) were injected intravenously in 8 normal subjects before and after oral administration of dexamethasone, 1.0 mg every 8 hr for 5 consecutive days. After dexamethasone, the mean basal plasma HTSH levels were significantly reduced, as was the plasma HTSH response to TRH: this reduced increase occurred in all subjects. The glucocorticoid did not alter significantly the serum thyroxine and triiodothyronine uptake. The data obtained are compatible with a direct inhibiting action of dexamethasone at pituitary level.

Key words

Hypothalamic-Pituitary-Thyroid System - Thyrotropin-Releasing Hormone - Thyrotropin - Glucocorticoids

      >