Combinatorial effect of lower extremity blood flow restriction and low intensity endurance exercise on aorta of old male rats: Histomorphological and molecular approach

Objective: Given the importance of knowing the effects of blood flow restriction (BFR) plus exercise training (BFR training) on the cardiovascular system, present study conducted to determine the effect of combination of BFR with low intensity endurance exercise on aorta of old rats. Methods: Animal groups were control (CTL), sham (Sh), BFR, exercise (Ex), sham + exercise (Sh + Ex), and BFR + exercise (BFR + Ex). BFR induced by partial closing of the bilateral femoral arteries and duration of exercise was 10 weeks. Results: BFR induced increasing of aorta wall thickness and decreasing its elastin/collagen ratio. Training alone increased the expression of apelin (P < 0.05) and angiotensin AT2 receptor (AT2R) (P < 0.01 versus CTL, Sh and P < 0.05 versus BFR groups) and the elastin/collagen ratio (P < 0.001) but, decreased the expression of angiotensin AT1 receptor (AT1R) (P < 0.01 versus CTL, Sh and BFR groups), the AT1R/AT2R ratio and the wall thickness (P < 0.001) of aorta. In Ex + BFR group, the expression of mentioned receptors increased and reached to more than levels of Ex groups, and the AT1R/AT2R ratio reduced in comparison with CTL, Sh and BFR and was higher than training groups (P < 0.5). Exercise also reversed the negative effect of BFR on elastin/collagen ratio and wall thickness. Conclusion: The beneficial effects of low intensity endurance exercise on aorta of aged male rats are conserved partially in presence of BFR. (C) 2018 Association for Research into Arterial Structure and Physiology. Published by Elsevier B.V. All rights reserved.