Ultrastructural changes in the adrenal gland in terms of age and gender-related

Year 2024, Volume: 8 Issue: 2, 113 - 119, 25.10.2024

Nejat Ünlükal , Abdullah Şentürk

https://doi.org/10.47748/tjvr.1465125

Abstract

Objectives: The adrenal glands are endocrine organs that synthesise hormones with crucial functions in the body. This irreplaceable structure performs multiple functions, from metabolism of carbohydrates, fats and proteins to sex development. Any disorder concerning the adrenal glands can give rise to life-threatening conditions. The aging process inevitably affects the adrenal glands. The effects of ageing are marked by a rise in cortisol secretion in the zona fasciculata and a decrease in androgen secretion in the zona reticularis. Elevated cortisol levels in the blood disturb most bodily systems in favour of catabolism, amplifying the cellular decline and destruction that accompanies ageing. The deterioration of the adrenal glands relates not just to spongiocytes and chromaffin cells, but also to the endothelium, which enables circulation. It is clear that a decline in vascular function will have a negative impact on endocrine activities. Our study aims to explore the influence of ageing on the adrenal glands in rats, analysing sex-specific ultrastructural scales. Materials and Methods: A total of 28 Sprague-Dawley rats, 14 males and 14 females, were planned to be used in the study. Of these 28 rats, 4 females and 4 males will constitute the control group. The rats in the control group will be approximately 10 weeks old, and the rats in the experimental group, which will represent the aged group, will be 19 weeks old. All animals in the study will be anaesthetised and then sacrificed by removal of the heart. The right and left common carotid arteries were removed from the sacrificed animals. Collected vessels prepared for TEM examination. For each animal, at least four TEM images were taken from four different sections from the same block. Results: Our findings demonstrate that the ageing process not only affects spongiocytes within the adrenal gland, but also contributes to the deterioration of endothelial cells. As anticipated, our results indicate the presence of senescence and apoptosis in endothelial cells. The observed vascular separations and ruptures are due to the endothelial deterioration. Spongiocytes experienced hypertrophy to compensate for the functional deficiencies following a decrease in their number due to ageing. Elevated levels of lipofuscin, lipid droplets, and lysosomes were discovered in spongiocytes. Impaired endothelium potentially contributes to certain changes in spongiocytes. Conclusions: While ageing-related changes appear similar in both genders, males tend to be more impacted.

Keywords

Adrenal gland, Endothelium, Ultrastructural, Endocrine, Gender-dependent difference

Ethical Statement

The study was approved by the Ethical Committee of the Faculty of Medicine of Baskent University. The ethics approval number: is 2009/16.

Supporting Institution

There is no funding.

Project Number

No

Thanks

We would like to thank Prof. Dr. Gülten KARABAY and Prof. Dr. Attila DAĞDEVİREN for guiding us in this study. We also thank the technicians at Başkent University Histology and Embryology Department for their help in laboratory studies.

References

• Augustin HG, Koh GY. Organotypic vasculature: From descriptive heterogeneity to functional pathophysiology. Science. 2017; 357(6353):2379.
• Chen-Pan C, Yamamoto Y, Ito Y, Pan IJ, Hayashi Y. A new type of cell death, the protruded type, observed in the adrenal gland of normal rats. J Vet Med Sci. 1996; 58(4):373-376.
• Costanzo L. Costanzo physiology. Philadelphia: Elsevier Health Sciences; 2021. pp.427-440.
• Ferrari E, Cravello L, Muzzoni B, et al. Age-related changes of the hypothalamic pituitary adrenal axis: pathophysiological correlates. Eur J Endocrinol. 2001; 144(4):319-329.
• Hall JE, Hall ME. Guyton and Hall textbook of medical physiology. Philadelphia: Elsevier Health Sciences; 2020. pp.955-972.
• Hansen JT. Netter's clinical anatomy. Philadelphia: Elsevier Health Sciences; 2019. pp.203-204.
• Hornsby PJ. Aging of the human adrenal cortex. Ageing Res Rev. 2002; 1(2):229-242.
• Hornsby PJ. Aging of the human adrenal cortex. Sci Aging Knowledge Environ. 2004; 35:6.
• Jameson JL, DeGroot LJ, De Kretser DM, et al. Endocrinology: adult and pediatric. 7th ed. Philadelphia: Elsevier Inc.; 2016; pp.2-26.
• Kierszenbaum AL, Tres L. Histology and cell biology: An Introduction to Pathology. Philadelphia: Elsevier Health Sciences; 2019. pp. 593-601.
• L Mescher A. (2013). Junqueira’s Basic Histology: Text and Atlas. United States: McGraw-Hill Companies, Inc.; 2013; pp.354-359.
• Parker CR, Mixon RL, Brissie RM, Grizzle WE. Aging alters zonation in the adrenal cortex of men. J Clin Endocrinol Metab. 1997; 82(11):3898-3901.
• Rebuffat P, Belloni AS, Rocco S, et al. The effects of ageing on the morphology and function of the zonae fasciculata and reticularis of the rat adrenal cortex. Cell Tissue Res. 1992; 270(2):265-272.
• Schaeffer M, Hodson DJ, Lafont C, Mollard P. (2011). Endocrine cells and blood vessels work in tandem to generate hormone pulses. J Mol Endocrinol. 2011; 47(2):59- 66.
• Scioli MG, Bielli A, Arcuri G, Ferlosio A, Orlandi A. Ageing and microvasculature. Vasc Cell. 2014; 6:19.
• Shaposhnikov VM. The ultrastructural features of secretory cells of some endocrine glands in aging. Mech Ageing Dev. 1985; 30(2):123-142.
• Stupina AS, Shaposhnikov VM. Age and ultrastructural features of adrenal capillaries in rats following ACTH administration and in insulin shock. Biull Eksp Biol Med. 1981; 92(8):89-91.
• Ungvari Z, Labinskyy N, Gupte S, et al. Dysregulation of mitochondrial biogenesis in vascular endothelial and smooth muscle cells of aged rats. Am J Physiol Heart Circ Physiol. 2008; 294(5):2121-2128.
• Warde KM, Smith LJ, Basham KJ. Age-related Changes in the Adrenal Cortex: Insights and Implications. J Endocr Soc. 2023; 7(9):97.
• Yiallouris A, Tsioutis C, Agapidaki E, et al. (2019). Adrenal aging and its implications on stress responsiveness in humans. Front Endocrinol (Lausanne). 2019; 10:54.