The effect of acute exercise on the secretion of corticotropin-releasing factor, arginine vasopressin, and adrenocorticotropin as measured in pituitary venous blood from the horse.
Abstract: We have used the technique which we have developed for collecting pituitary venous blood from conscious, undisturbed horses to study the effect of acute vigorous exercise on the secretion of CRF, arginine vasopressin (AVP) and ACTH. Pituitary venous (pit) blood was collected every 1-5 min from nine trained racehorses at rest in the stable. The horses then trotted quietly for 10 min, after which they galloped as fast as possible for 4-6 min, before returning to the stable where sampling continued. In Exp 1 (n = 5) no blood samples were taken during exercise, whereas in Exp 2 (n = 4), pit blood was collected every 30 sec during exercise. Immediately after exercise, significant elevations in heart rate (P less than 0.001), body temperature (P less than 0.01) and hematocrit (P less than 0.001) were observed as compared with preexercise values. Jugular cortisol levels were higher after exercise (301.9 +/- 35.2 nmol/liter; mean +/- SEM) than before (187.3 +/- 34.8; P less than 0.01; n = 9). Likewise, jugular AVP levels increased with exercise (before, 0.65 +/- 0.11 pmol/liter; after 3.2 +/- 0.6; P less than 0.01; n = 6), whereas jugular CRF was not altered by exercise (before, 0.38 +/- 0.08 pmol/liter; after, 0.93 +/- 0.31; n = 6; NS). In Exp 1, no significant changes in pit ACTH, AVP, or CRF were observed after exercise. However in Exp 2 when pit blood was sampled during exercise all horses showed an immediate and dramatic rise in ACTH (P less than 0.01) and AVP (P less than 0.005) secretion which peaked during galloping with mean fractional changes above resting levels of 23.6 +/- 9.9 for ACTH and 51.7 +/- 24.0 for AVP. After exercise pit AVP levels were not different from resting, whereas ACTH remained elevated (11.4 +/- 6.9-fold above resting levels). By contrast, pit CRF levels were not altered by exercise. In both experiments together, pit AVP and ACTH concentrations were correlated in eight of the nine horses, whereas pit CRF and ACTH concentrations were positively correlated in only one of seven horses. We conclude that acute exercise causes a transient increase in ACTH secretion which occurs synchronously with an increase in AVP secretion. CRF does not appear to play a major role in mediating the initial ACTH response to exercise.
Publication Date: 1991-01-01 PubMed ID: 1846116DOI: 10.1210/endo-128-1-65Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
- Research Support
- U.S. Gov't
- P.H.S.
Summary
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This research investigates how vigorous, short-term exercise impacts the secretion of corticotropin-releasing factor (CRF), arginine vasopressin (AVP) and adrenocorticotropin (ACTH) in racehorses. The study finds that acute exercise leads to a temporary increase in AVP and ACTH secretion, but CRF levels remain unchanged.
Research Methodology
- The research conducted involved a unique technique developed by the authors. This technique allowed for the collection of pituitary venous blood from calm, undisturbed horses.
- The study included nine trained racehorses, which were initially observed during rest in the stable. The horses were then subjected to mild exercise – a 10-minute trot – followed by vigorous exercise – a gallop lasting between 4 and 6 minutes.
- The effect of exercise on the secretion levels of CRF, AVP, and ACTH was examined. Blood was collected at intervals between 1-5 minutes during periods of rest and every 30 seconds during exercise.
Research Findings
- Vigorous exercise significantly increased the heart rate, body temperature, and hematocrit of the horses. Additionally, cortisol and AVP levels in the jugular vein were higher immediately post-exercise as compared to the pre-exercise state.
- However, concentrations of CRF, a hormone associated with stress responses, remained unchanged with exercise.
- In the second experiment where pituitary blood samples were collected during exercise, there was a significant and rapid increase in ACTH and AVP secretion, peaking during the galloping phase.
- Interestingly, after the exercise, the AVP levels returned to the resting state, whereas ACTH remained significantly elevated.
- In contrast to AVP and ACTH, the levels of CRF in the pituitary blood did not change with exercise.
Conclusion
- The findings suggest that vigorous, short-term exercise triggers an increase in AVP and ACTH secretion, however, CRF does not appear to significantly influence this initial response to exercise.
- The correlation of AVP and ACTH concentrations in eight out of the nine horses suggests a synchronous response to acute exercise. This is in contradiction to the CRF response, which only correlated with ACTH in one out of seven horses, indicating that it may play a minor role in mediating the initial ACTH response to exercise.
Cite This Article
APA
Alexander SL, Irvine CH, Ellis MJ, Donald RA.
(1991).
The effect of acute exercise on the secretion of corticotropin-releasing factor, arginine vasopressin, and adrenocorticotropin as measured in pituitary venous blood from the horse.
Endocrinology, 128(1), 65-72.
https://doi.org/10.1210/endo-128-1-65 Publication
Researcher Affiliations
- Department of Endocrinology, Princess Margaret Hospital, Christchurch, New Zealand.
MeSH Terms
- Adrenocorticotropic Hormone / blood
- Adrenocorticotropic Hormone / metabolism
- Animals
- Arginine Vasopressin / blood
- Arginine Vasopressin / metabolism
- Body Temperature
- Corticotropin-Releasing Hormone / blood
- Corticotropin-Releasing Hormone / metabolism
- Female
- Heart Rate
- Horses / physiology
- Hydrocortisone / blood
- Hydrocortisone / metabolism
- Male
- Physical Exertion
- Pituitary Gland / blood supply
- Pituitary Gland / metabolism
Grant Funding
- 38322 / PHS HHS
Citations
This article has been cited 19 times.- Kirkwood NC, Hughes KJ, Stewart AJ. Prospective Case Series of Clinical Signs and Adrenocorticotrophin (ACTH) Concentrations in Seven Horses Transitioning to Pituitary Pars Intermedia Dysfunction (PPID). Vet Sci 2022 Oct 17;9(10).
- Kam YN, McKenzie K, Coyle M, Bertin FR. Repeatability of a thyrotropin-releasing hormone stimulation test for diagnosis of pituitary pars intermedia dysfunction in mature horses. J Vet Intern Med 2021 Nov;35(6):2885-2890.
- Kitaura T, Sato F, Hada T, Ishimaru M, Kodama R, Nambo Y, Watanabe G, Taya K. Influence of exercise and emotional stresses on secretion of prolactin and growth hormone in Thoroughbred horses. J Equine Sci 2021 Jun;32(2):49-53.
- Horn R, Stewart AJ, Jackson KV, Dryburgh EL, Medina-Torres CE, Bertin FR. Clinical implications of using adrenocorticotropic hormone diagnostic cutoffs or reference intervals to diagnose pituitary pars intermedia dysfunction in mature horses. J Vet Intern Med 2021 Jan;35(1):560-570.
- Gehlen H, Jaburg N, Merle R, Winter J. Can Endocrine Dysfunction Be Reliably Tested in Aged Horses That Are Experiencing Pain?. Animals (Basel) 2020 Aug 14;10(8).
- Adamo S, Pigna E, Lugarà R, Moresi V, Coletti D, Bouché M. Skeletal Muscle: A Significant Novel Neurohypophyseal Hormone-Secreting Organ. Front Physiol 2018;9:1885.
- Spelta CW. Equine pituitary pars intermedia dysfunction: current perspectives on diagnosis and management. Vet Med (Auckl) 2015;6:293-300.
- Roelfsema F, Aoun P, Takahashi PY, Erickson D, Yang R, Veldhuis JD. Regulation of Pulsatile and Entropic ACTH Secretion Under Fixed Exogenous Secretagogue Clamps. J Clin Endocrinol Metab 2017 Jul 1;102(7):2611-2619.
- Costa A, Rossi E, Scicchitano BM, Coletti D, Moresi V, Adamo S. Neurohypophyseal Hormones: Novel Actors of Striated Muscle Development and Homeostasis. Eur J Transl Myol 2014 Sep 23;24(3):3790.
- Rendle DI, Duz M, Beech J, Parkin T, Durham AE. Investigation of single and paired measurements of adrenocorticotropic hormone for the diagnosis of pituitary pars intermedia dysfunction in horses. J Vet Intern Med 2015 Jan;29(1):355-61.
- Weinstein TA, Bales KL, Maninger N, Hostetler CM, Capitanio JP. Early involvement in friendships predicts later plasma concentrations of oxytocin and vasopressin in juvenile rhesus macaques (Macaca mulatta). Front Behav Neurosci 2014;8:295.
- Costa A, Toschi A, Murfuni I, Pelosi L, Sica G, Adamo S, Scicchitano BM. Local overexpression of V1a-vasopressin receptor enhances regeneration in tumor necrosis factor-induced muscle atrophy. Biomed Res Int 2014;2014:235426.
- Kato M, Kurakane S, Nishina A, Park J, Chang H. The blood lactate increase in high intensity exercise is depressed by Acanthopanax sieboldianus. Nutrients 2013 Oct 16;5(10):4134-44.
- Iranmanesh A, Rochester DF, Liu J, Veldhuis JD. Impaired adrenergic- and corticotropic-axis outflow during exercise in chronic obstructive pulmonary disease. Metabolism 2011 Nov;60(11):1521-9.
- Goebel M, Stengel A, Wang L, Reeve J Jr, Taché Y. Lipopolysaccharide increases plasma levels of corticotropin-releasing hormone in rats. Neuroendocrinology 2011;93(3):165-73.
- Moresi V, Garcia-Alvarez G, Pristerà A, Rizzuto E, Albertini MC, Rocchi M, Marazzi G, Sassoon D, Adamo S, Coletti D. Modulation of caspase activity regulates skeletal muscle regeneration and function in response to vasopressin and tumor necrosis factor. PLoS One 2009;4(5):e5570.
- Keenan DM, Alexander S, Irvine C, Veldhuis JD. Quantifying nonlinear interactions within the hypothalamo-pituitary-adrenal axis in the conscious horse. Endocrinology 2009 Apr;150(4):1941-51.
- Holmes SJ, Florkowski CM, Evans MJ, Ellis MJ, Livesey JH, Donald RA, Espiner EA. Metyrapone induced increase in plasma corticotropin is not associated with changes in peripheral venous arginine vasopressin or corticotropin releasing factor. J Endocrinol Invest 1993 Nov;16(10):787-92.
- Menzies-Gow NJ. Equine Pituitary Pars Intermedia Dysfunction. Vet Sci 2025 Aug 20;12(8).
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