Simulated microgravity-induced aortic remodeling
AUTOR(ES)
Tuday, Eric C.
FONTE
American Physiological Society
RESUMO
We have previously shown that microgravity and simulated microgravity induce an increase in human and rat aortic stiffness. We attempted to elucidate the mechanism(s) responsible for this increase in stiffness. We hypothesize that an alteration in vessel wall collagen or elastin content or in extracellular matrix (ECM) cross-linking either individually or in a combination is responsible for the increased vessel stiffness. Rats underwent hindlimb unweighting (HLU) for a period of 7 days to simulate microgravity. The contribution of ECM cross-linking to the vessel wall stiffness was evaluated by measuring aortic pulse wave velocity following inhibition of the cross-linking enzymes lysyl oxidase (LOX) and transglutaminase (tTG) and the nonenzymatic advanced glycation end product cross-linking pathway during HLU. Aortic collagen and elastin content was quantified using established colorimetric assays. Collagen subtype composition was determined via immunofluorescent staining. The increase in aortic pulse wave velocity after HLU was significantly attenuated in the LOX and tTG inhibition groups compared with saline (1.13 ± 0.11 vs. 3.00 ± 0.15 m/s, LOX vs. saline, P < 0.001; 1.16 ± 0.25 vs. 3.00 ± 0.15 m/s, tTG vs. saline, P < 0.001). Hydroxyproline content, a measure of collagen content, was increased in all groups after HLU (2.01 ± 0.62 vs. 3.69 ± 0.68% dry weight, non-HLU vs. HLU, P = 0.009). Collagen subtype composition and aortic elastin content were not altered by HLU. Together, these data indicate that HLU-induced increases in aortic stiffness are due to both increased aortic collagen content and enzyme cross-linking activity.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2692776Documentos Relacionados
- Sympathetic neural responses to mental stress during acute simulated microgravity
- Artificial gravity maintains skeletal muscle protein synthesis during 21 days of simulated microgravity
- Role and Regulation of σs in General Resistance Conferred by Low-Shear Simulated Microgravity in Escherichia coli
- Maternal Intake of Flaxseed During Lactation and Exercise Training Protect Against Salt Overload-Induced Aortic Remodeling in Adult Offspring
- Alterations in Aortic Cellular Constituents during Thoracic Aortic Aneurysm Development : Myofibroblast-Mediated Vascular Remodeling