Elastic and collagen fibers are the two major extracellular matrix (ECM) constituents in large elastic arteries and the primary load-bearing components of the arterial wall. Cardiovascular risk factors, such as age, high blood pressure, obesity, diabetes, and their co-occurrence referred to as metabolic syndrome, directly impact the biomechanical function of arteries. The objective of this study is to provide understandings on the structure and function of elastic arteries under aging, hypertension, and metabolic syndrome using a coupled experimental-modeling approach that integrates multiphoton imaging, mechanical characterization, and constitutive modeling.
In this study, we showed that consumption of a high fat high sucrose diet induced metabolic syndrome accelerated arterial remodeling in a mouse model. Aging- and diet-induced arterial remodeling was manifested by a significantly reduced capability of elastic energy storage. Our study further revealed that aging adversely impacted the mechanical homeostasis in elastic arteries with altered structural inhomogeneity in elastic lamellae. Specifically, the uneven thickening of inter-lamellar space and the increased unfolding of inner lamellar layers, resulted in compromised mechanical homeostasis that was manifested by a nonuniform lamellar stretching and stress distribution in the arterial wall. These microstructural changes are likely related to arterial remodeling.
Hypertension has long been associated with arterial stiffening and renal sympathetic nervous system plays an important regulatory role in blood pressure. Renal denervation has been emerged as a potential therapeutic approach to resistant hypertension by selectively removing the renal nerves and therefore attenuating sympathetic outflow to the kidney. In this study, we investigated the effects of renal denervation on the biomechanical response and microstructure of elastic arteries using a rat model of spontaneous hypertension. Our results showed that renal denervation effectively reduced blood pressure and reversed the biomechanical properties of carotid arteries under physiological pressure. In the meantime, arteries remained intact after renal denervation without observable changes in the ECM microstructure. Our study provides interesting initial findings on the effect of renal denervation on large elastic arteries mechanical response and microstructure. Future studies are needed to fully reveal the complex interplay between renal sympathetic nervous system and blood pressure regulation. / 2024-09-15T00:00:00Z
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/46887 |
| Date | 15 September 2023 |
| Creators | Gkousioudi, Anastasia |
| Contributors | Zhang, Yanhang Katherine |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
| Rights | Attribution 4.0 International, http://creativecommons.org/licenses/by/4.0/ |
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