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Transmural Variation of Collagen Orientation and Structure Distributions in the Right Pulmonary Arterial Wall
Author(s) -
Pursell Erica,
Valdez-Jasso Daniela
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2020.34.s1.06659
Subject(s) - adventitia , tortuosity , pulmonary artery , pulmonary hypertension , collagen fiber , medicine , anatomy , arterial wall , blood pressure , artery , pathology , biomedical engineering , cardiology , materials science , composite material , porosity
Pulmonary arterial hypertension (PAH) is a disease characterized by elevated blood pressure (mean pulmonary arterial pressure above 25 mmHg. Remodeling of pulmonary arteries due to this elevated blood pressure compromises their normal physiological function. Our previous work showed that the right pulmonary artery significantly stiffens circumferentially in PAH and collagen fibers become engaged and significantly aligned in the medial layer (Pursell et al 2016). To better understand the changes in tissue mechanical response, here we explore the distributions of collagen orientation and tortuosity through the vessel wall. Methods To induce PAH, four male Sprague‐Dawley rats were injected with 60 mg/kg monocrotaline. Once PAH was established (4 weeks post‐injection), pulmonary arteries were harvested, and collagen imaged via multiphoton microscopy. A custom MATLAB code was then used to determine collagen fiber orientation and tortuosity. Results MPM images of collagen fibers from the intima, media, and adventitia of normotensive and hypertensive rat RPAs were traced with our custom MATLAB code. In the hypertensive animals, fiber direction and tortuosity varied more between vascular wall layers than those of normotensive animals. Conclusions While our previous study only examined the medial layer, this study determined that fiber distribution varies throughout the vessel wall. This will significantly affect the mechanics or behavior of pulmonary vessels. Therefore, future studies will need to incorporate collagen structures from multiple vessel layers to better understand the relationship between vascular remodeling and mechanics.