Adrenal cortex response to adrenocorticotropic hormone in dairy cattle.
Adult dairy cows were treated with a range of doses (0.0125mg to 0.4mg) of synthetic ACTH1-24 and the plasma cortisol response was measured. Peak response was independent of dose. Higher doses of ACTH had a more prolonged effect such that the integrated response was dose dependent. Dose response curves were examined by regression analyses. Individual cows had a significant effect on y-axis intercept but not on the slope of the regression lines examined. A dose rate of 0.05mg ACTH iv was identified as a suitable dose rate for use in clinical assessment of adrenal cortex function, with 0, 50 and 120 min following ACTH being critical sampling times to identify the response.
Verkerk
G A
GA
Dairying Research Corporation, Hamilton, New Zealand.
Macmillan
K L
KL
McLeay
L M
LM
D000302:Adrenal Cortex / Q000187:drug effects*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006854:Hydrocortisone / Q000097:blood
D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone