Endocrinology Vol. 140, No. 5 2422-2425
Copyright © 1999 by The Endocrine Society
Corticoid Concentrations Are Increased in the Plasma and Urine of Ewes with Naturally Occurring Scrapie
F. Schelcher,
N. Picard-Hagen,
V. Laroute,
V. Gayrard,
M. A. Popot,
O. Andreoletti and
P. L. Toutain
Unité associée INRA de Physiopathologie Respiratoire
des Ruminants (F.S., O.A.), Unité associée INRA de
Physiopathologie et Toxicologie Expérimentales (N.P.-H., V.L.,
P.L.T.), Ecole Nationale Vétérinaire de Toulouse, 30176
Toulouse, France, L.A.B. Fédération Nationale des
Sociétés de Courses (M.A.P.), 92290 Chatenay, Malabry,
France
Address all correspondence and requests for reprints to P. L. Toutain, Ecole Nationale Veterinaire de Toulouse, 23 Chemin des Capelles, Toulouse 31076, France.
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Abstract
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The 24-h pattern of corticoid plasma concentrations was determined in
scrapie-affected ewes during the clinical phase of the disease. Twenty
one ewes (8 healthy and 13 scrapie-affected ewes) were subjected to
24-h blood sampling sessions. Urine samples were simultaneously
obtained during the clinical stage of the disease and in healthy ewes.
The scrapie diagnosis was performed by histopathology. Plasma and
urinary corticoids were assayed using HPLC methods. Mean plasma and
urinary levels of corticoid (cortisol, 20ß-dihydrocortisol,
cortisone) of scrapie-affected ewes were greater than those observed in
healthy ewes. 20ß-dihydrocortisol appeared to be the main cortisol
metabolite in ewes. The intra-individual variations of
20ß-dihydrocortisol plasma concentrations were lower than the
corresponding plasma cortisol concentrations due to the dampening
effect of the metabolic process on the short term variations of
cortisol secretion. This dampening mechanism was amplified in urine,
the urinary concentrations integrating cortisol production over the
period preceding sampling. For these reasons, 20ß-dihydrocortisol
could present a potential interest for a non invasive diagnostic test
of transmissible spongiform encephalopathies. The pathophysiological
consequences of an excessive exposure to cortisol on development of the
neurogenerative process are discussed.
Received November 4, 1998.
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