In vivo studies on the effects of ovine corticotrophin-releasing hormone, arginine vasotocin, arginine vasopressin, and haloperidol on adrenocortical function in the racing pigeon (Columba livia domestica).
This study investigates the effects of in vivo administration of pituitary stimulants in racing pigeons (Columba livia domestica). Plasma corticosterone concentrations were measured following intravenous administration of ovine corticotrophin-releasing hormone (oCRH) (0.1, 1, 10, and 100 micrograms/kg), arginine vasopressin (AVP) (0.01, 0.1, 1, and 10 micrograms/kg), arginine vasotocin (AVT) (0.01, 0.1, 1, and 5 micrograms/kg), and haloperidol (0.05, 0.5, and 5 micrograms/kg). Compared with mammals the pituitary-adrenocortical system of the pigeon appeared to be less sensitive to stimulation with oCRH, although high doses were well tolerated and gave a clear response. Both AVP and AVT stimulated corticosterone secretion, AVT in a more pronounced dose-dependent manner than AVP. The natural neurohypophysial peptide in birds, AVT, was less well tolerated in high doses than AVP. The clear response to haloperidol indicates that the hypothalamo-pituitary-adrenocortical system is under dopaminergic inhibition. Of the pituitary stimulants tested AVP (10 micrograms/kg) and oCRH (100 micrograms/kg) are the most appropriate for testing the integrity of the pituitary-adrenocortical system in the pigeon.
Westerhof
I
I
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
Lumeij
J T
JT
Mol
J A
JA
van den Brom
W E
WE
Rijnberk
A
A
D000302:Adrenal Cortex / Q000187:drug effects*; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D010856:Columbidae / Q000502:physiology*; D003345:Corticosterone / Q000097:blood; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D012756:Sheep; D014668:Vasotocin / Q000494:pharmacology*
D001127:Arginine Vasopressin; D003346:Corticotropin-Releasing Hormone; D006220:Haloperidol; D014668:Vasotocin; D003345:Corticosterone