Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses
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 t...
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MDPI AG
2022-01-01
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| author | Sophia L. Hinrichsen Ka Y. Yuen Elizabeth L. Dryburgh François-René Bertin Allison J. Stewart |
| author_facet | Sophia L. Hinrichsen Ka Y. Yuen Elizabeth L. Dryburgh François-René Bertin Allison J. Stewart |
| author_sort | Sophia L. Hinrichsen |
| collection | DOAJ |
| description | 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 (<i>p</i> = 0.003) on immunoreactive ACTH concentrations, and this effect was greater in PPID-negative horses (<i>p</i> = 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. |
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| spelling | doaj.art-ec361714bb2d432db7c3a88d053852d52023-11-23T15:47:56ZengMDPI AGAnimals2076-26152022-01-0112332410.3390/ani12030324Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in HorsesSophia L. Hinrichsen0Ka Y. Yuen1Elizabeth L. Dryburgh2François-René Bertin3Allison J. Stewart4School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, AustraliaSchool of Veterinary Science, The University of Queensland, Gatton, QLD 4343, AustraliaBoehringer Ingelheim Animal Health Australia Pty. Ltd., North Ryde, NSW 2113, AustraliaSchool of Veterinary Science, The University of Queensland, Gatton, QLD 4343, AustraliaSchool of Veterinary Science, The University of Queensland, Gatton, QLD 4343, AustraliaPituitary 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 (<i>p</i> = 0.003) on immunoreactive ACTH concentrations, and this effect was greater in PPID-negative horses (<i>p</i> = 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.https://www.mdpi.com/2076-2615/12/3/324endocrinologypituitary pars intermedia dysfunctionchemiluminescent assaygeriatric |
| spellingShingle | Sophia L. Hinrichsen Ka Y. Yuen Elizabeth L. Dryburgh François-René Bertin Allison J. Stewart Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses Animals endocrinology pituitary pars intermedia dysfunction chemiluminescent assay geriatric |
| title | Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses |
| title_full | Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses |
| title_fullStr | Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses |
| title_full_unstemmed | Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses |
| title_short | Short-Term Effects of Temperature and Thyrotropin-Releasing Hormone Stimulation on Adrenocorticotropin Stability in Horses |
| title_sort | short term effects of temperature and thyrotropin releasing hormone stimulation on adrenocorticotropin stability in horses |
| topic | endocrinology pituitary pars intermedia dysfunction chemiluminescent assay geriatric |
| url | https://www.mdpi.com/2076-2615/12/3/324 |
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