Location: Livestock Issues ResearchTitle: A dual challenge of corticotropin releasing hormone and vasopressin alters immune cell profiles in beef heifers Author
|Carroll, Jeffery - Jeff Carroll|
|Buntyn, Joe - University Of Nebraska|
|Sieren, Sara - University Of Nebraska|
|Jones, Steven - University Of Nebraska|
|Schmidt, Ty - University Of Nebraska|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/12/2014
Publication Date: 7/25/2014
Citation: Carroll, J.A., Sanchez, N.C., Buntyn, J.O., Sieren, S.E., Jones, S.J., Schmidt, T.B. 2014. A dual challenge of corticotropin releasing hormone and vasopressin alters immune cell profiles in beef heifers. Journal of Animal Science Supplement. 92(E-Suppl. 2):33. Abstract #65.
Technical Abstract: The duration and magnitude of cortisol release can have different effects on the immune response. Over the last decade, studies have suggested that acute stress, when cortisol is elevated for a short duration of time, can be immuno-stimulatory rather than immuno-suppressive. This study was designed to determine the effect of an induced cortisol release, via a dual corticotropin releasing hormone (CRH) and vasopressin (VP) challenge, on changes in immune cell profiles of beef heifers. Four d prior to the challenge, ten heifers (605 ± 13 kilograms) were fitted with indwelling jugular cannulas and indwelling vaginal temperature (VT) recording devices that measured VT continuously at 5-minutes intervals. On day 0, heifers were challenged intravenously with 0.3 micrograms/kilogram body weight bovine CRH and 1.0 micrograms/kilograms body weight bovine vasopressin concurrently. Two, whole blood samples were collected at 30-minute intervals from -2 to 8 hours relative to the challenge at 0 hour. One vacutainer containing EDTA was collected for complete blood cell count (CBC) analysis, and the second was collected in a 9-mililiter monovette serum tube. After collection, serum was isolated and stored at -80C until analyzed for cortisol concentrations by ELISA. There was a time effect (P < 0.001) for VT, cortisol, and CBC variables. A multi-phasic response was observed for VT, with VT initially increasing (P = 0.05; relative to 0 hour) within 15 minute post-challenge. Serum cortisol concentrations increased (P < 0.001) immediately after the challenge, reaching maximum concentrations between 0.5 to 2 hours post-challenge and then continually decreasing until reaching baseline concentrations at 6 hours post-challenge (P = 0.17 for 0 h vs 6 hours). Concentrations of white blood cells and lymphocytes increased (P < 0.001) 2 hours after CRH/VP challenge, and remained elevated for the duration of the challenge period. Monocyte concentrations initially decreased 1 hour post-challenge (P < 0.001), and returned to baseline concentrations by 2 hours post-challenge (P = 0.08 for 0 h vs 2 hours). In contrast, neutrophil concentrations decreased (P = 0.02) 3 hours post-challenge, and remained decreased throughout the duration of the challenge. These data demonstrate that immune cell populations are influenced by an acute activation of the hypothalamic-pituitary-adrenal axis. This supports the conclusions that acute stress primes the immune response in preparation for an immune challenge, and suggests that acute stress experienced during management procedures may have beneficial effects on the immune system.