<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>Global warming causes an increased ambient temperature and prolonged heatwaves during the summer, which represent stressogenic factors affecting the hypothalamo-pituitary-adrenocortical (HPA) axis in mammals. The aim of  this study was to investigate the effects of  long-term (7-60 days) exposure to moderately elevated ambient temperature (35 ± 1°C) on the histological aspect and secretory ability of  pituitary adrenocorticotropic (ACTH) cells, as well as on the corticosterone output, in adult rats. Stereological parameters of ACTH cells were estimated upon immunohistochemistry. The blood concentrations of ACTH and corticosterone were determined by immunoassays. The volume of ACTH cells in rats exposed to moderately high temperature for 7, 14, 21, 30 and 60 days decreased (p&lt;0.05) by 18.1%, 14.5%, 13.5%, 8.6% and 14.2% respectively, compared to the same parameter in the controls. The volume density of ACTH cells in the groups exposed to elevated temperature for 7, 14, 21, 30 and 60 days decreased (p&lt;0.05) by 40.0%, 33.3%, 26.7%, 13.3% and 26.7% respectively, in comparison with control rats. The plasma concentration of ACTH varied differently (p&lt;0.05) with the duration of exposure to the elevated temperature. The serum concentration of corticosterone was decreased (p&lt;0.05) by 54.9%, 24.4%, 29.9%, 21.1% and 24.4% in groups subjected to moderately high temperature for 7, 14, 21, 30 and 60 days respectively, all compared to the control value. Despite some signs of functional recovery of ACTH cells during the treatment, the impression is that the long-term character of this stressor overcomes the capacity of the HPA axis for resistance.</p>
</abstract>

Global warming causes an increased ambient temperature and prolonged heatwaves during the summer, which represent stressogenic factors affecting the hypothalamo-pituitary-adrenocortical (HPA) axis in mammals. The aim of  this study was to investigate the effects of  long-term (7-60 days) exposure to moderately elevated ambient temperature (35 ± 1°C) on the histological aspect and secretory ability of  pituitary adrenocorticotropic (ACTH) cells, as well as on the corticosterone output, in adult rats. Stereological parameters of ACTH cells were estimated upon immunohistochemistry. The blood concentrations of ACTH and corticosterone were determined by immunoassays. The volume of ACTH cells in rats exposed to moderately high temperature for 7, 14, 21, 30 and 60 days decreased (p<0.05) by 18.1%, 14.5%, 13.5%, 8.6% and 14.2% respectively, compared to the same parameter in the controls. The volume density of ACTH cells in the groups exposed to elevated temperature for 7, 14, 21, 30 and 60 days decreased (p<0.05) by 40.0%, 33.3%, 26.7%, 13.3% and 26.7% respectively, in comparison with control rats. The plasma concentration of ACTH varied differently (p<0.05) with the duration of exposure to the elevated temperature. The serum concentration of corticosterone was decreased (p<0.05) by 54.9%, 24.4%, 29.9%, 21.1% and 24.4% in groups subjected to moderately high temperature for 7, 14, 21, 30 and 60 days respectively, all compared to the control value. Despite some signs of functional recovery of ACTH cells during the treatment, the impression is that the long-term character of this stressor overcomes the capacity of the HPA axis for resistance.

The Effects of Long-Term Exposure to Moderate Heat on Rat Pituitary ACTH Cells: Histological and Hormonal Study

Faculty of Medicine, Department of Anatomy

Ss. Cyril and Methodius University in Skopje

Faculty of Veterinary Medicine-Skopje, Department of Functional Morphology

Acta Veterinaria

This work is licensed under the Creative Commons Attribution 4.0 International License.

Global warming causes an increased ambient temperature and prolonged heatwaves during the summer, which represent stressogenic factors affecting the...

The Effects of Long-Term Exposure to Moderate Heat on Rat Pituitary ACTH Cells: Histological and Hormonal Study

Publié en ligne: 05 avr. 2022

Pages: 1 - 15

Reçu: 24 sept. 2021

Accepté: 12 janv. 2022

DOI: https://doi.org/10.2478/acve-2022-0001

Mots clés
ACTH cells, elevated temperature, pituitary, rats, stereology

© 2022 Jovana Čukuranović Kokoris et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

The Effects of Long-Term Exposure to Moderate Heat on Rat Pituitary ACTH Cells: Histological and Hormonal Study

Publié en ligne: 05 avr. 2022

Pages: 1 - 15

Reçu: 24 sept. 2021

Accepté: 12 janv. 2022

DOI: https://doi.org/10.2478/acve-2022-0001

Mots clésACTH cells, elevated temperature, pituitary, rats, stereology

© 2022 Jovana Čukuranović Kokoris et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Mots clés
ACTH cells, elevated temperature, pituitary, rats, stereology