Serum concentrations of cortisol, sex hormones of adrenal origin, and adrenocortical steroid intermediates in healthy dogs following stimulation with two doses of cosyntropin.
OBJECTIVE
To compare the effects of 2 doses of cosyntropin (5 microg/kg vs 250 microg, IV) on serum concentrations of cortisol, sex hormones of adrenal origin, and adrenocortical steroid intermediates and determine the optimal sample collection time after adrenal stimulation with cosyntropin.


METHODS
10 healthy, privately owned, neutered dogs.


METHODS
Dogs were randomly assigned to initially receive cosyntropin at 5 microg/kg or as a total dose of 250 microg, IV. Dogs received the alternate dose 1 to 2 weeks later. Serum was obtained from blood samples collected before (0 minutes) and 30, 60, 90, and 120 minutes after cosyntropin administration.


RESULTS
Maximum stimulation of cortisol, androstenedione, progesterone, and 17-hydroxyprogesterone production was achieved at 60 minutes following IV administration of cosyntropin at 5 microg/kg or as a total dose of 250 microg. Serum estradiol concentration did not increase in response to either cosyntropin dose. For all hormones, no significant difference in serum hormone concentrations was found among sample collection times of 0, 30, 60, and 90 minutes when comparing the 2 doses of cosyntropin.


CONCLUSIONS
Cosyntropin, when administered at 5 microg/kg, IV, effectively stimulated maximum production of cortisol, sex hormones of adrenal origin, and adrenocortical steroid intermediates at 1 hour after administration.
Frank
Linda A
LA
Department of Small Animal Clinical Sciences, C247 Veterinary Teaching Hospital, University of Tennessee, Knoxville, TN 37996-4544, USA.
Davis
Jacqueline A
JA
Oliver
Jack W
JW
D019326:17-alpha-Hydroxyprogesterone / Q000097:blood*; D000302:Adrenal Cortex / Q000187:drug effects* / Q000378:metabolism; D000735:Androstenedione / Q000097:blood*; D000818:Animals; D003366:Cosyntropin / Q000008:administration & dosage*; D004285:Dogs; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D011863:Radioimmunoassay / Q000662:veterinary
D012739:Gonadal Steroid Hormones; D003366:Cosyntropin; D000735:Androstenedione; D019326:17-alpha-Hydroxyprogesterone; D006854:Hydrocortisone