FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Animals : an open access journal from MDPI2022; 12(3); 324; doi: 10.3390/ani12030324

Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses.

Abstract: Pituitary pars intermedia dysfunction (PPID) is diagnosed by increased basal or post thyrotropin-releasing hormone (TRH) stimulation ACTH concentrations. ACTH is known to be unstable; however, the effect of different temperatures and TRH stimulation on equine ACTH stability is poorly described. In total, 15 horses, including 8 PPID positive (ACTH > 35 pg/mL at baseline or >65 pg/mL 30 min after TRH stimulation), were divided into 2 groups: 9, including 5 PPID positive, with basal ACTH concentrations and 6, including 3 PPID positive, with post TRH stimulation ACTH concentrations. Whole blood was stored for 1 h at 4, 20, 30, 40, or 70 °C. After centrifugation, immunoreactive ACTH concentrations were determined using a chemiluminescent assay. Linear mixed effect models were used to detect the effects of temperature, PPID status, and TRH stimulation on the immunoreactive ACTH concentration. Temperature had a significant effect ( = 0.003) on immunoreactive ACTH concentrations, and this effect was greater in PPID-negative horses ( = 0.01), with the changes in immunoreactive ACTH concentrations being slightly unpredictably higher or lower than samples stored at 4 °C. Even at 20 °C, mean immunoreactive ACTH concentrations minimally changed by 5% in PPID horses and 12% in non-PPID horses after 1 h. No significant effect of TRH stimulation was identified. Although ACTH concentrations should ideally be determined from samples kept at 4 °C, samples inadvertently left at temperatures of up to 40 °C can provide valid results if analyzed within 1 h; however, this increases the risks of altered ACTH concentrations, occasionally influencing the diagnosis of PPID.
Get Full Text
Publication Date: 2022-01-28 PubMed ID: 35158648PubMed Central: PMC8833476DOI: 10.3390/ani12030324Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research investigates how different storage temperatures and thyrotropin-releasing hormone (TRH) stimulation impact the stability of Adrenocorticotropin (ACTH) hormone in horses, useful for diagnosing pituitary pars intermedia dysfunction (PPID). Conclusions emphasize the importance of maintaining blood samples at 4°C for reliable ACTH concentrations, although higher temperatures are deemed tolerable if analysis occurs within 60 minutes.

Objective and Methodology

  • The study aimed to explore how changing storage temperatures and TRH stimulation affect the stability of the ACTH hormone in horses, a crucial factor in diagnosing PPID.
  • The researchers worked with 15 horses; eight were determined PPID-positive, meaning they exhibited increased basal or post-TRH stimulation ACTH concentrations.
  • These horses were split into two groups: one group had nine horses with basal ACTH concentrations, including five PPID positive, while the other group had six horses, including three PPID positive, with post TRH stimulation ACTH concentrations.
  • The horse’s whole blood was stored at five different temperatures – 4°C, 20°C, 30°C, 40°C, and 70°C – for one hour before undergoing a chemiluminescent assay to determine immunoreactive ACTH concentrations.
  • A statistical model – linear mixed effect – was used to identify potential effects of temperature, PPID status, and TRH stimulation on the concentration of ACTH in its immunoreactive form.

Findings and Conclusions

  • Temperature proved to have a significant effect on immunoreactive ACTH concentrations, and this effect was more pronounced in PPID-negative horses.
  • Even a minor increase to 20°C led to 5% change in ACTH concentrations in PPID horses and 12% in non-PPID horses after one hour.
  • No detectable effect from TRH stimulation was found on ACTH concentrations.
  • The researchers concluded that, for optimal ACTH concentration results, samples should ideally be kept at 4°C. However, results could still be considered valid if stored at temperatures up to 40°C, as long as analysis is undertaken within the hour.
  • The study highlights potential risks for altered ACTH concentrations resulting from temperature discrepancies, which could influence diagnostic accuracy for PPID.

Cite This Article

APA
Hinrichsen SL, Yuen KY, Dryburgh EL, Bertin FR, Stewart AJ. (2022). Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses. Animals (Basel), 12(3), 324. https://doi.org/10.3390/ani12030324

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 12
Issue: 3
PII: 324

Researcher Affiliations

Hinrichsen, Sophia L
  • School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia.
Yuen, Ka Y
  • School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia.
Dryburgh, Elizabeth L
  • Boehringer Ingelheim Animal Health Australia Pty. Ltd., North Ryde, NSW 2113, Australia.
Bertin, François-René
  • School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia.
Stewart, Allison J
  • School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia.

Grant Funding

  • 1 / CSRD VA

Conflict of Interest Statement

Elizabeth L. Dryburgh is employed by Boehringer-Ingelheim Pty Ltd., and Allison J. Stewart and François-René Bertin have consulted for Boehringer-Ingelheim Pty Ltd.

References

This article includes 28 references
  1. Miller MA, Moore GE, Bertin FR, Kritchevsky JE. What's New in Old Horses? Postmortem Diagnoses in Mature and Aged Equids.. Vet Pathol 2016 Mar;53(2):390-8.
    doi: 10.1177/0300985815608674pubmed: 26459516google scholar: lookup
  2. McGowan TW, Pinchbeck GP, McGowan CM. Prevalence, risk factors and clinical signs predictive for equine pituitary pars intermedia dysfunction in aged horses.. Equine Vet J 2013 Jan;45(1):74-9.
    doi: 10.1111/j.2042-3306.2012.00578.xpubmed: 22594955google scholar: lookup
  3. Rohrbach BW, Stafford JR, Clermont RS, Reed SM, Schott HC 2nd, Andrews FM. Diagnostic frequency, response to therapy, and long-term prognosis among horses and ponies with pituitary par intermedia dysfunction, 1993-2004.. J Vet Intern Med 2012 Jul-Aug;26(4):1027-34.
    doi: 10.1111/j.1939-1676.2012.00932.xpubmed: 22524260google scholar: lookup
  4. Miller MA, Pardo ID, Jackson LP, Moore GE, Sojka JE. Correlation of pituitary histomorphometry with adrenocorticotrophic hormone response to domperidone administration in the diagnosis of equine pituitary pars intermedia dysfunction.. Vet Pathol 2008 Jan;45(1):26-38.
    doi: 10.1354/vp.45-1-26pubmed: 18192571google scholar: lookup
  5. McFarlane D, Miller LM, Craig LE, Dybdal NO, Habecker PL, Miller MA, Patterson JS, Cribb AE. Agreement in histologic assessments of the pituitary pars intermedia in aged horses.. Am J Vet Res 2005 Dec;66(12):2055-9.
    doi: 10.2460/ajvr.2005.66.2055pubmed: 16379646google scholar: lookup
  6. Horn R, Bamford NJ, Afonso T, Sutherland M, Buckerfield J, Tan RHH, Secombe CJ, Stewart AJ, Bertin FR. Factors associated with survival, laminitis and insulin dysregulation in horses diagnosed with equine pituitary pars intermedia dysfunction.. Equine Vet J 2019 Jul;51(4):440-445.
    doi: 10.1111/evj.13041pubmed: 30417404google scholar: lookup
  7. Horn R, Bertin FR. Evaluation of combined testing to simultaneously diagnose pituitary pars intermedia dysfunction and insulin dysregulation in horses.. J Vet Intern Med 2019 Sep;33(5):2249-2256.
    doi: 10.1111/jvim.15617pmc: PMC6766519pubmed: 31498947google scholar: lookup
  8. 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.
    doi: 10.1111/jvim.16017pmc: PMC7848300pubmed: 33368633google scholar: lookup
  9. Beech J, Boston R, Lindborg S, Russell GE. Adrenocorticotropin concentration following administration of thyrotropin-releasing hormone in healthy horses and those with pituitary pars intermedia dysfunction and pituitary gland hyperplasia.. J Am Vet Med Assoc 2007 Aug 1;231(3):417-26.
    doi: 10.2460/javma.231.3.417pubmed: 17669045google scholar: lookup
  10. Beech J, McFarlane D, Lindborg S, Sojka JE, Boston RC. α-Melanocyte--stimulating hormone and adrenocorticotropin concentrations in response to thyrotropin-releasing hormone and comparison with adrenocorticotropin concentration after domperidone administration in healthy horses and horses with pituitary pars intermedia dysfunction.. J Am Vet Med Assoc 2011 May 15;238(10):1305-15.
    doi: 10.2460/javma.238.10.1305pubmed: 21568777google scholar: lookup
  11. Evans MJ, Livesey JH, Ellis MJ, Yandle TG. Effect of anticoagulants and storage temperatures on stability of plasma and serum hormones.. Clin Biochem 2001 Mar;34(2):107-12.
    doi: 10.1016/S0009-9120(01)00196-5pubmed: 11311219google scholar: lookup
  12. Jane Ellis M, Livesey JH, Evans MJ. Hormone stability in human whole blood.. Clin Biochem 2003 Mar;36(2):109-12.
    doi: 10.1016/S0009-9120(02)00440-Xpubmed: 12633759google scholar: lookup
  13. Wu ZQ, Xu HG. Preanalytical stability of adrenocorticotropic hormone depends on both time to centrifugation and temperature.. J Clin Lab Anal 2017 Sep;31(5).
    doi: 10.1002/jcla.22081pmc: PMC6816861pubmed: 27735096google scholar: lookup
  14. Gehlen H, Bradaric Z. [Study on the reproducibility of ACTH concentrations in plasma of horses with and without equine Cushing syndrome].. Berl Munch Tierarztl Wochenschr 2013 Jul-Aug;126(7-8):350-6.
    pubmed: 23901591
  15. Prutton JS, Kass PH, Watson JL, Pusterla N. Pre-analytical stability of adrenocorticotrophic hormone from healthy horses in whole blood, plasma and frozen plasma samples.. Vet J 2015 Apr;204(1):123-4.
    doi: 10.1016/j.tvjl.2015.02.010pubmed: 25744807google scholar: lookup
  16. Rendle DI, Litchfield E, Gough S, Cowling A, Hughes KJ. The effects of sample handling and N-phenylmaleimide on concentration of adrenocorticotrophic hormone in equine plasma.. Equine Vet J 2015 Sep;47(5):587-91.
    doi: 10.1111/evj.12319pubmed: 24980684google scholar: lookup
  17. Al-Kayiem HH, Sidik MFBM, Munusammy YRAL. Study on the thermal accumulation and distribution inside a parked car cabin.. Am. J. Appl. Sci. 2010;7:784–789.
    doi: 10.3844/ajassp.2010.784.789google scholar: lookup
  18. Hu K, Stewart AJ, Yuen KY, Hinrichsen S, Dryburgh EL, Bertin FR. The effect of freeze-thaw cycles on determination of immunoreactive plasma adrenocorticotrophic hormone concentrations in horses.. J Vet Intern Med 2020 May;34(3):1350-1356.
    doi: 10.1111/jvim.15771pmc: PMC7255672pubmed: 32255541google scholar: lookup
  19. Hicks GR, Fraser NS, Bertin FR. Changes Associated with the Peri-Ovulatory Period, Age and Pregnancy in ACTH, Cortisol, Glucose and Insulin Concentrations in Mares.. Animals (Basel) 2021 Mar 20;11(3).
    doi: 10.3390/ani11030891pmc: PMC8003915pubmed: 33804751google scholar: lookup
  20. Stewart AJ, Hackett E, Bertin FR, Towns TJ. Cortisol and adrenocorticotropic hormone concentrations in horses with systemic inflammatory response syndrome.. J Vet Intern Med 2019 Sep;33(5):2257-2266.
    doi: 10.1111/jvim.15620pmc: PMC6766528pubmed: 31512777google scholar: lookup
  21. Durham AE, McGowan CM, Fey K, Tamzali Y, van der Kolk JH. Pituitary pars intermedia dysfunction: Diagnosis and treatment.. Equine Vet. Educ. 2014;26:216–223.
    doi: 10.1111/eve.12160google scholar: lookup
  22. Carmalt JL, Mortazavi S, McOnie RC, Allen AL, Unniappan S. Profiles of pro-opiomelanocortin and encoded peptides, and their processing enzymes in equine pituitary pars intermedia dysfunction.. PLoS One 2018;13(1):e0190796.
    doi: 10.1371/journal.pone.0190796pmc: PMC5757946pubmed: 29309431google scholar: lookup
  23. McGilvray TA, Knowles EJ, Harris PA, Menzies-Gow NJ. Comparison of immunofluorescence and chemiluminescence assays for measuring ACTH in equine plasma.. Equine Vet J 2020 Sep;52(5):709-714.
    doi: 10.1111/evj.13227pubmed: 31955443google scholar: lookup
  24. Irvine KL, Burt K, Hill AJ, Shaw S, Papasouliotis K. Initial analytic quality assessment and method comparison of an immunoassay for adrenocorticotropic hormone measurement in equine samples.. Vet Clin Pathol 2016 Mar;45(1):154-63.
    doi: 10.1111/vcp.12326pubmed: 26756538google scholar: lookup
  25. Knowles EJ, Moreton-Clack MC, Shaw S, Harris PA, Elliott J, Menzies-Gow NJ. Plasma adrenocorticotropic hormone (ACTH) concentrations in ponies measured by two different assays suggests seasonal cross-reactivity or interference.. Equine Vet J 2018 Sep;50(5):672-677.
    doi: 10.1111/evj.12797pubmed: 29247453google scholar: lookup
  26. Banse HE, Schultz N, McCue M, Geor R, McFarlane D. Comparison of two methods for measurement of equine adrenocorticotropin.. J Vet Diagn Invest 2018 Mar;30(2):233-237.
    doi: 10.1177/1040638717752216pmc: PMC6505866pubmed: 29284383google scholar: lookup
  27. Schreiber CM, Stewart AJ, Kwessi E, Behrend EN, Wright JC, Kemppainen RJ, Busch KA. Seasonal variation in results of diagnostic tests for pituitary pars intermedia dysfunction in older, clinically normal geldings.. J Am Vet Med Assoc 2012 Jul 15;241(2):241-8.
    doi: 10.2460/javma.241.2.241pubmed: 22765372google scholar: lookup
  28. Funk RA, Stewart AJ, Wooldridge AA, Kwessi E, Kemppainen RJ, Behrend EN, Zhong Q, Johnson AK. Seasonal changes in plasma adrenocorticotropic hormone and α-melanocyte-stimulating hormone in response to thyrotropin-releasing hormone in normal, aged horses.. J Vet Intern Med 2011 May-Jun;25(3):579-85.
    doi: 10.1111/j.1939-1676.2011.0712.xpubmed: 21457320google scholar: lookup

Citations

This article has been cited 4 times.
  1. 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).
    doi: 10.3390/vetsci9100572pubmed: 36288186google scholar: lookup
  2. Kirkwood NC, Hughes KJ, Stewart AJ. Pituitary Pars Intermedia Dysfunction (PPID) in Horses. Vet Sci 2022 Oct 10;9(10).
    doi: 10.3390/vetsci9100556pubmed: 36288169google scholar: lookup
  3. Wu Z, Qiu L, Zhang M, Chen G. Report of a rare case of childhood adrenocortical carcinoma and literature review. Urol Case Rep 2025 Jul;61:103113.
    doi: 10.1016/j.eucr.2025.103113pubmed: 40677937google scholar: lookup
  4. Neufang L, Ramos J, Eda S, Flatland B, Giori L. Initial development of a rapid, portable, stall-side ELISA for the measurement of equine adrenocorticotropic hormone. J Vet Diagn Invest 2025 Jan;37(1):208-211.
    doi: 10.1177/10406387241285453pubmed: 39320416google scholar: lookup
Subscribe to our newsletter
Join 99,780 horse owners like you who receive our email updates on horse health and nutrition.