Effects of synthetic ovine corticotropin-releasing hormone on plasma concentrations of immunoreactive adrenocorticotropin, alpha-melanocyte-stimulating hormone, and cortisol in dogs with naturally acquired adrenocortical insufficiency.
We evaluated the effect of ovine corticotropin-releasing hormone (CRH) on plasma immunoreactive (IR) concentrations of ACTH, alpha-melanocyte-stimulating hormone, and cortisol in 8 dogs with naturally acquired adrenocortical insufficiency. Of the 7 dogs with primary adrenal insufficiency, 6 had markedly high basal plasma IR-ACTH concentrations and exaggerated ACTH responses to CRH administration, whereas 1 dog that was receiving replacement doses of prednisone at the time of testing had normal basal IR-ACTH concentrations and a nearly normal response to CRH. In contrast, the 1 dog with secondary adrenocortical insufficiency had undetectable basal plasma IR-ACTH concentrations, which failed to increase after administration of CRH. Basal plasma alpha-melanocyte-stimulating hormone concentrations in the dogs with adrenal insufficiency were within normal range and were unaffected by CRH administration. In all 8 dogs with adrenal insufficiency, plasma cortisol concentrations were low and did not increase after administration of CRH. Therefore, stimulation with CRH produced 2 patterns of plasma IR-ACTH response when administered to dogs with naturally acquired adrenal insufficiency. Dogs with primary adrenal insufficiency had high basal plasma IR-ACTH concentrations and exaggerated responses to CRH, whereas the dog with secondary adrenal insufficiency had undetectable basal plasma concentrations of IR-ACTH that did not increase after stimulation with CRH.
Peterson
M E
ME
Animal Medical Center and Cornell University Medical College, New York, NY 10021.
Kemppainen
R J
RJ
Orth
D N
DN
D000305:Adrenal Cortex Hormones / Q000097:blood*; D000309:Adrenal Insufficiency / Q000097:blood / Q000662:veterinary*; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004283:Dog Diseases / Q000097:blood*; D004285:Dogs; D005260:Female; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D010907:Pituitary Hormones / Q000097:blood*; D000521:alpha-MSH / Q000097:blood
D000305:Adrenal Cortex Hormones; D010907:Pituitary Hormones; D000521:alpha-MSH; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D006854:Hydrocortisone