Moderate Exercise Does Not Reverse Adverse Effects Of Stress On Cutaneous Wound Healing

Our aim was to observe the effect of moderate exercise in cutaneous wound healing of mice chronically stressed. We divided the mice in three groups: sham, stressed‐sedentary and stressed‐exercised. The animals exercised were submitted to a treadmill protocol for eight weeks. After 6 weeks of training, stressed group was submitted to rotational stress, until the end of experiment. On the 8th week, two excisional wounds were performed. After lesion, the exercise stopped. Blood lactate was not increased in exercise group, so exercise was moderate. Exercise impaired the contraction and reepitalization of wounds comparing to the stressed‐sedentary and sham groups. Stressed‐sedentary group presented higher amounts of inflammatory cells (neutrophils and macrophages), and a thinner neo‐epidermis, compared to exercised group. Myofibroblasts α‐SMA positive and blood vessels with pericytes were increased in exercised group. Stressed‐sedentary group presented less and immature collagen fibers when compared to exercised group. Last, we measured the levels of scar lipids peroxides and observed that this tax was increased on exercised group when compared to sedentary group. Taken together these results suggest that exercise impairs wound closure in stressed animals, but the scar formed seems to present a better quality.