Impaired Angiogenesis in Aging Is Associated with Alterations in Vessel Density, Matrix Composition, Inflammatory Response, and Growth Factor Expression

Abstract

It is generally accepted that angiogenesis is delayed in aging. To define the effects of age on the neovascular response, polyvinyl alcohol sponges were implanted SC in young (6–8 months old, n = 11) and aged (23-25 months old, n = 13) mice and sampled at 14 and 19 days. Angiogenic invasion was significantly delayed in aged mice at 14d relative to young at 14d (% area of invasion 9.0 ± 3.7 vs 19.0 ± 5.6; p = 0.02). Although microvessel morphology and basement membrane composition were similar between the age groups, a significant decrease in capillary density was noted in aged tissues at 14d (7.5 ± 4.1) and 19d (12.1 ± 2.8) relative to young at 14d (18.7 ± 2.3) ( p3 ± 7.3 × 10³) to 19d (34.9 × 10³ ± 17 × 10³). We conclude that angiogenesis in aging is not merely delayed, but is altered due to multiple impairments.