Study of the Biomechanical and Histological Properties of the Abdominal Aorta of Diabetic Rats Exposed to Cigarette Smoke

• Published in: Journal of vascular research Vol. 56; no. 5; pp. 255 - 266
• Main Authors: Barão, Felipe Trajano de Freitas, Barão, Vivian Helena Pedroso, Gornati, Vitor Cervantes, Silvestre, Gina Camillo Rocha, Silva, Alexandre Queiroz, Lacchini, Silvia, de Castro, Michele Mazzaron, De Luccia, Nelson, da Silva, Erasmo Simão
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland S. Karger AG 01.10.2019
• Subjects: Abdominal aneurysm; Animals; Aorta, Abdominal - metabolism; Aorta, Abdominal - pathology; Aorta, Abdominal - physiopathology; Aortic Aneurysm, Abdominal - etiology; Aortic Aneurysm, Abdominal - metabolism; Aortic Aneurysm, Abdominal - pathology; Aortic Aneurysm, Abdominal - physiopathology; Biomechanical Phenomena; Biomechanics; Collagen - metabolism; Complications and side effects; Diabetes; Diabetes Mellitus, Experimental - complications; Disease Progression; Elastic Tissue - pathology; Health aspects; Histology, Pathological; Male; Matrix Metalloproteinase 2 - metabolism; Medical research; Medicine, Experimental; Physiological aspects; Rats, Wistar; Regional Blood Flow; Research Article; Risk Factors; Smoke - adverse effects; Smoking; Stress, Mechanical; Time Factors; Tobacco Products - adverse effects; Brazil; Biomechanics; Aorta; Histology; Matrix metalloproteinase 2; Diabetes mellitus; Cigarette smoke
• ISSN: 1018-1172; 1423-0135
• DOI: 10.1159/000502688

Introduction: In spite of the great relevance of abdominal aortic aneurysm, its etiopathogenesis is not fully understood. The biomechanical and histological study of the aortic wall may contribute to this elucidation. Methods: Seventy-five male Wistar rats were divided into 4 groups: control (CG), smoker (SG), diabetic (DG), and diabetic + smoker (DSG). The SG and DSG rats were exposed to cigarette smoke for 30 min/day, 5 days a week. Diabetes was induced by the intravenous injection of streptozotocin. After 16 weeks, the abdominal aorta was collected for biomechanical, histological, and matrix metalloproteinase 2 (MMP-2) activity analyses. Results: The valid biomechanical tests of 52 specimens were analyzed: 11 in the CG, 10 in the DG, 16 in the SG, and 15 in the DSG. The biomechanical analysis of the fragments showed no differences between the control, DG, SG, and DSG. Collagen deposition also did not present a significant difference between the studied groups. The total count of elastic fibers was higher in diabetic rats (DG and DSG) than in the SG. The inflammatory response observed in all experimental groups was significantly more intense than in the CG. Compared to the DSG, MMP-2 activity showed a significant decrease in the DG. Conclusions: Resistance and elasticity did not present a difference between the CG and the DG, SG, and DSG. Compared to the CG, the total count of elastic fibers, fragmentation of the elastic lamina, pericellular matrix deposition, and cell loss/substitution in the tunica media showed significant alterations in the aortic walls of the DG, SG, and DSG. MMP-2 activity was lower in the DG aorta than in the DSG aorta.