NR ARUF
AU Viguie,C.; Chilliard,Y.; Gayrard,V.; Picard-Hagen,N.; Monget,P.; Dutour,A.; Toutain,P.L.
TI Alterations of somatotropic function in prion disease in sheep
QU Journal of Endocrinology 2004 Nov; 183(2): 427-35
PT journal article
AB This study aimed at investigating the possible linkage between natural scrapie and alterations of the somatotropic axis. Scrapie-affected ewes exhibited 2-fold higher mean GH concentrations during both autumn and spring. GH pulse frequencies were higher in scrapie-affected ewes than in control animals (mean+/-S.E.M. number of pulses/24 h: 10.4+/-0.9 and 7.6+/-0.9 for scrapie-affected and control ewes respectively) suggesting the involvement of central mechanisms. GH secretion induced by administration of an alpha(2)-adrenergic agonist, which acts centrally to stimulate GH secretion, was similar between healthy and scrapie-affected ewes (ratios of the area under the curve (AUC) of GH concentration after to the GH AUC before the agonist administration were 3.6+/-1.6 and 4.9+/-1.0 for scrapie-affected and control ewes respectively). Finally, humoral markers and parameters of the metabolic status were determined to test the hypothesis that scrapie-associated alterations of GH secretion could be related to disruption of metabolic homeostasis. Glucose, insulin and urea plasma concentrations were higher in scrapie-affected than in healthy ewes. Neither leptin nor IGF-I levels were affected by scrapie. Total thyroxine (T4) was decreased in scrapie-affected ewes but free T4 and total and free triiodothyronine were not modified. In conclusion, our results showed the existence in scrapie-affected ewes of endocrine and metabolic alterations typical of acute illness proceeding, at least in part, from central mechanisms.
MH Acute Disease; Adrenergic alpha-Agonists/pharmacology; Animals; Blood Glucose/analysis; Female; Growth Hormone/blood/*secretion; Insulin/blood; Male; Pituitary Gland/cytology/drug effects/*secretion; Research Support, Non-U.S. Gov't; Scrapie/blood/*physiopathology; Seasons; Secretory Rate/drug effects; Sheep; Thyroxine/blood; Urea/blood
AD UMR 181, Experimental Pathophysiology and Toxicology, INRA National Veterinary School of Toulouse, 31076 Toulouse cedex 3, France. c.viguie@envt.fr
SP englisch
PO England