Ultrastructural Changes of the Microcirculation with Aging

Abstract

IntroductionAging is associated with an increase in capillary basement membrane (BM) thickness which may contribute to the decreased working capacity in elderly. The aim of this study was to elucidate if age‐related changes is present in both the upper and lower extremities, and to what extent endurance training can reduce BM thickness.MethodsFive healthy older men (66±3 yr.) completed 8 weeks of one‐legged knee extensor training (3x/week). Muscle biopsies were obtained from the m. vastus lateralis (VL) and the deltoid muscle before the training intervention. After the training intervention, biopsies from VL of both the trained leg and the control leg was obtained. The capillary‐to‐fiber (C/F) ratio was determined with light microscope, and morphometry analysis was completed after transmission electron microscopy (TEM). Data were analyzed by one‐way repeated measures ANOVA.ResultsAt baseline, the BM thickness was higher in the VL compared to the deltoid muscle (p<0.05), whereas there was no difference on the C/F ratio. After 8 weeks of training, the BM thickness was decreased in the VL of the trained leg (~24%, p<0.05), and it was thinner compared to the control leg (p<0.05). The C/F ratio was higher in the trained leg compared to the control leg (p<0.05).ConclusionThese preliminary results indicate that the age‐related alterations in BM thickness are more pronounced in the lower extremities of healthy aged men and that exercise training results in a local thinning of the BM.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.