Circulating plasma factors contribute to age-associated arterial stiffness

Previous findings from our laboratory showed that age-related increases in large elastic artery stiffness in mice are associated with remodeling of the extracellular matrix (ECM), as indicated by increased collagen I expression, and oxidative stress, as indicated by increased nitrotyrosine staining. Here we tested the hypothesis that circulating factors in plasma contribute to arterial oxidative stress, ECM remodeling and stiffening. Nitrotyrosine, collagen I and elastic modulus, a measure of intrinsic mechanical stiffness, were determined in aortic rings from young (6 mo, n=4) male C57 mice cultured for 72 hours in media containing 10% plasma from either young (Yplasma) or old (Oplasma) mice. Compared with Yplasma, aortic rings incubated in Oplasma demonstrated increased NT abundance (3.11 ± 0.50 vs. 1.00 ± 0.30 AU, p<0.05), collagen I (1.66 ± 0.18 vs. 1.00 ± 0.12 AU, p<0.05) and elastic modulus (2780 ± 570 vs. 1768 ± 188 kPa, p=0.05). These preliminary results are consistent with the hypothesis that unk...