Comparison of Histomorphometric Characteristics of Heart and Aorta in Young Adult and Aged Rats

Öz

Aim: The aim of this study was to compare the histomorphometric and immunohistochemical properties of the heart and aorta in young adult and aged rats. Material and Methods: Sixteen female Wistar albino rats, eight young adult (6 months old, female, 233.25±13.85 g) and rats were used in the study. The rats were sacrificed under high dose anaesthesia and heart and aortic tissues were collected. Ventricular and septum interventiculare thicknesses were measured on the heart tissues, tunica media, tunica intima thickness and aortic diameter were measured histomorphometrically on the aortic tissues. In addition, Inducible Nitric Oxide Synthase (iNOS) in the smooth muscle cells of the tunica media of the aorta and occludin protein levels in the aorta and heart endothelium were examined by immunohistochemical method and histological scoring was performed. Results: As a result of statistical analysis, body weight, heart weight, heart weight/body weight ratio, tunica media and intima thicknesses, and aortic diameters were found to be statistically significantly higher in aged rats compared to young adult rats (p<0.05). Among the cardiac measurements, only the left ventricle/heart weight ratio was found to be statistically significantly higher in young adults than in aged rats (p<0.05). In addition, according to the H scoring of the data obtained as a result of immunohistochemical staining for iNOS protein, iNOS protein level was found to be higher in aged rats than in young rats (p<0.05). Immunohistochemical staining for occludin in aorta and heart endothelial cells of aged rats revealed weaker staining compared to young rats. Conclusion: In general, our study emphasises the importance of understanding the histomorphometric changes that occur in heart and aortic tissue as a result of aging. Further research is needed to better understand the mechanisms underlying these age-related changes and to identify potential therapeutic targets for the prevention and treatment of cardiovascular diseases in elderly individuals

Anahtar Kelimeler

• Ageing
• aorta
• heart
• histomorphometry
• iNOS

Genç Erişkin ve Yaşlı Sıçanlarda Kalp ve Aort’un Histomorfometrik Özelliklerinin Karşılaştırılması

Öz

Amaç: Bu çalışmanın amacı, genç erişkin ve yaşlı sıçanlarda kalp ve aortun histomorfometrik ve immünohistokimyasal özelliklerini karşılaştırmaktır. Gereç ve Yöntemler: Çalışmada sekiz genç erişkin (6 aylık, dişi, 233,25±13,85 g) ve sekiz yaşlı (24 aylık, dişi, 257,12±17,48 g) olmak üzere toplam on altı dişi Wistar albino sıçan kullanıldı. Deneye dahil edilen sıçanlar yüksek doz anestezi altında sakrifiye edilerek kalp ile aort dokuları toplandı. Kalp dokuları üzerinden ventrikül ve septum interventiculare kalınlıkları ölçülürken aort dokusu üzerinde tunica media ve tunica intima kalınlığı, aort çapı histomorfometrik olarak ölçüldü. Ayrıca aortaların tunica medialarının düz kas hücrelerinde Inducible Nitric Oxide Synthase (iNOS) ve aorta ve kalp endotelinde okludin protein düzeyleri immünohistokimyasal yöntemle incelendi ve histolojik skorlama yapıldı. Bulgular: Yapılan istatistiksel analiz sonucunda yaşlı sıçanlarda vücut ağırlığı, kalp ağırlığı, kalp ağırlığı/ vücut ağırlığı oranı, tunica media ve intima kalınlıkları, aort çapları genç erişkin sıçanlara göre istatistiksel olarak anlamlı seviyede yüksek olduğu tespit edildi (p<0.05). Kalp ölçümlerinden sadece sol ventrikül/ kalp ağırlığı oranının genç erişkinlerde yaşlı sıçanlara göre istatistiksel olarak anlamlı seviyede yüksek olduğu belirlendi (p<0.05). Ayrıca iNOS proteini için yapılan immünohistokimyasal boyama sonucunda elde edilen verilerin H skorlamasına göre yaşlı sıçanlarda iNOS protein düzeyi gençlere göre yüksek bulundu (p<0.05). Yaşlı sıçanların aorta ve kalp endotel hücrelerinde okludin için yapılan immünohistokimyasal boyama sonucunda genç sıçanlara göre daha zayıf boyanma gözlendi. Sonuç: Genel olarak çalışmamız, yaşlanmanın bir sonucu olarak kalp ve aort dokusunda meydana gelen histomorfometrik değişikliklerin anlaşılmasının önemini vurgulamaktadır. Yaşa bağlı bu değişikliklerin altında yatan mekanizmaları daha iyi anlamak ve yaşlı bireylerde kardiyovasküler hastalıkların önlenmesi ve tedavisine yönelik potansiyel terapötik hedefleri belirlemek için daha fazla araştırmaya ihtiyaç vardır.

Anahtar Kelimeler

• Aort
• histomorfometri
• iNOS
• kalp
• yaşlanma

Kaynakça

1. 1. Bruce R Troen. The biology of aging. Mt Sinai J Med. 2003;70(1):3-22.
2. 2. Strait JB, Lakatta EG. Aging-Associated Cardiovascular Changes and Their Relationship to Heart Failure. Heart Fail Clin. 2012 January;8(1):143-64.
3. 3. North BJ, Sinclair DA. The Intersection Between Aging and Cardiovascular Disease. Circ Res. 2012 April 13;110(8):1097- 108.
4. 4. Bentov I, Reed MJ. The effect of aging on the cutaneous microvasculature. Microvasc Res. 2015 July;100:25-31.
5. 5. Özerkan Çakan F. Changes in cardiovascular physiology in the elderly. Turk Kardiyol Dernegi Arsivi-Arch Turk Soc Cardiol [İnternet]. 2017 [a.yer 23 Mart 2024]; Erişim adresi: https://archivestsc. com/jvi.aspx?un=TKDA-89856
6. 6. Fonseca DA, Antunes PE, Antunes MJ, Cotrim MD. Histomorphometric analysis of the human internal thoracic artery and relationship with cardiovascular risk factors. Pizzi C, editör. PLOS ONE. 25 Ocak 2019;14(1):e0211421.
7. 7. Sengupta, Pallav. The laboratory rat: relating its age with human’s. International journal of preventive medicine, 2013, 4.6: 624.
8. 8. Borges RSDM, Medeiros ADM, Silva JGD, Paiva RRLT, Costa HDS, Oliveira MFD, vd. Morphometry of the heart of greater rhea ( Rhea americana americana , Linnaeus, 1758). Anat Histol Embryol. 2021 March;50(2):345-9.

9. 9. Altaweel R, Shatarat A, Badran D, Abu Tarboush NM. The effects of irisin on the rat thoracic aorta: a histological study. Folia Morphol. 2022 December 08;81(4):923-30.
10. 10. Inan M, Uz YH, Kizilay G, Topcu-Tarladacalisir Y, Sapmaz-Metin M, Akpolat M, vd. Protective effect of sildenafil on liver injury induced by intestinal ischemia/reperfusion. J Pediatr Surg. 2013 August;48(8):1707-15.
11. 11. Mompeó-Corredera B, Hernández-Morera P, Castaño- González I, Quintana-Montesdeoca MDP, Mederos-Real N. Regions of the human renal artery: histomorphometric analysis. Anat Cell Biol. 2022 September 30 ;55(3):330-340.
12. 12. Miura K. Tunica intima compensation for reduced stiffness of the tunica media in aging renal arteries as measured with scanning acoustic microscopy. Yu J, editör. PLOS ONE. 2020 November 04;15(11):e0234759.
13. 13. Westerterp KR. Changes in physical activity over the lifespan: impact on body composition and sarcopenic obesity. Obes Rev. 2018 December;19(S1):8-13.
14. 14. Miyasaka K, Ichikawa M, Kawanami T, Kanai S, Ohta M, Sato N, vd. Physical activity prevented age-related decline in energy metabolism in genetically obese and diabetic rats, but not in control rats. Mech Ageing Dev. 2003 February;124(2):183-90.
15. 15. Rising R, Lifshitz F. Energy expenditures & physical activity in rats with chronic suboptimal nutrition. Nutr Metab. 2006 December; 3(1):11.
16. 16. Nagai Y, Metter EJ, Earley CJ, Kemper MK, Becker LC, Lakatta EG, vd. Increased Carotid Artery Intimal-Medial Thickness in Asymptomatic Older Subjects With Exercise-Induced Myocardial Ischemia. Circulation. 1998 October 13 ;98(15):1504-9.
17. 17. Virmani R, Avolio AP, Mergner WJ, Robinowitz M, Herderick EE, Guo SY, vd. Effect of Aging on Aortic Morphology in Populations with High and Low Prevalence of Hypertension and Atherosclerosis. 1991;139(5).
18. 18. Laurent S. Defining vascular aging and cardiovascular risk. J Hypertens. 2012 June ;30:S3-8.
19. 19. Xu X, Wang B, Ren C, Hu J, Greenberg DA, Chen T, vd. Age-related Impairment of Vascular Structure and Functions. Aging Dis. 2017;8(5):590.
20. 20. Stefanadis C, Karayannacos PE, Boudoulas H, et al. Age-related changes in the aortic root structure and function in normal humans. J Am Coll Cardiol. 2014;20(5):1044-1050. doi:10.1016/S0735-1097(02)02159-8.
21. 21. Guzik TJ, Touyz RM. Oxidative stress, inflammation, and vascular aging in hypertension. Hypertension. 2017;70(4):660-667. doi:10.1161/HYPERTENSIONAHA.117.07887.
22. 22. North BJ, Sinclair DA. The intersection between aging and cardiovascular disease. Circ Res. 2012;110(8):1097-1108. doi:10.1161/CIRCRESAHA.111.246876.
23. 23. Soskic SS. Regulation of Inducible Nitric Oxide Synthase (iNOS) and its Potential Role in Insulin Resistance, Diabetes and Heart Failure. Open Cardiovasc Med J. 2011 July 07 ;5(1):153-63.
24. 24. Radu-Ionita F, Ţintoiu IC, Rosu A, Bontas E, Cochior D, Bolohan R, vd. Aging Aorta—Cellular Mechanisms. Içinde: New Approaches to Aortic Diseases from Valve to Abdominal Bifurcation [Internet]. Elsevier; 2018 [a.yer 2024 March 25]. s. 3-23. Erişim adresi: https://linkinghub.elsevier.com/retrieve/pii/ B9780128099797000018
25. 25. De Moudt S, Hendrickx JO, Neutel C, De Munck D, Leloup A, De Meyer GRY, vd. Progressive aortic stiffness in aging C57Bl/6 mice displays altered contractile behaviour and extracellular matrix changes. Commun Biol. 2022 June 17 ;5(1):605.
26. 26. Lee JG, Takemoto DJ. Role of claudin-5 in blood-brain barrier integrity during aging. Neurobiol Aging. 2021;107:196-203.
27. 27. Jia W, Lu R, Yin L, et al. The role of tight junctions in cardiovascular diseases: from mechanism to clinical manifestation. J Cardiovasc Transl Res. 2022;15(3):570-581.
28. 28. Feng Q, Lu X, Jones DL, Shen J, Arnold JMO. Increased Inducible Nitric Oxide Synthase Expression Contributes to Myocardial Dysfunction and Higher Mortality After Myocardial Infarction in Mice. Circulation. 2001 August 07 ;104(6):700-4.
29. 29. Muniyappa R, Sowers JR. Role of nitric oxide and oxidative stress in cardiovascular disease. Curr Hypertens Rep. 2013;15(5):408-415.