Ghrelin-stimulation test in the diagnosis of canine pituitary dwarfism.
This study investigated whether ghrelin, a potent releaser of growth hormone (GH) secretion, is a valuable tool in the diagnosis of canine pituitary dwarfism. The effect of intravenous administration of ghrelin on the release of GH and other adenohypophyseal hormones was investigated in German shepherd dogs with congenital combined pituitary hormone deficiency and in healthy Beagles. Analysis of the maximal increment (i.e. difference between pre- and maximal post-ghrelin plasma hormone concentration) indicated that the GH response was significantly lower in the dwarf dogs compared with the healthy dogs. In none of the pituitary dwarfs, the ghrelin-induced plasma GH concentration exceeded 5 microg/l at any time. However, this was also true for 3 healthy dogs. In all dogs, ghrelin administration did not affect the plasma concentrations of ACTH, cortisol, TSH, LH and PRL . Thus, while a ghrelin-induced plasma GH concentration above 5 microg/l excludes GH deficiency, false-negative results may occur.
Bhatti
S F M
SF
Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Sofie.Bhatti@UGent.be
De Vliegher
S P
SP
Mol
J A
JA
Van Ham
L M L
LM
Kooistra
H S
HS
D000818:Animals; D004283:Dog Diseases / Q000175:diagnosis*; D004285:Dogs; D004393:Dwarfism, Pituitary / Q000175:diagnosis* / Q000662:veterinary*; D005188:False Negative Reactions; D005260:Female; D054439:Ghrelin; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism; D007262:Infusions, Intravenous; D008297:Male; D036361:Peptide Hormones / Q000008:administration & dosage; D012680:Sensitivity and Specificity
D054439:Ghrelin; D036361:Peptide Hormones; D013006:Growth Hormone