Gender differences in muscle inflammation after eccentric exercise

Abstract

Unaccustomed exercise is followed by delayed-onset muscle soreness and morphological changes in skeletal muscle. Animal studies have demonstrated that women have an attenuated response to muscle damage. We studied the effect of eccentric exercise in untrained male (n = 8) and female (n = 8) subjects using a unilateral exercise design [exercise (Ex) and control (Con) legs]. Plasma granulocyte counts [before (Pre) and 48 h after exercise (+48h)] and creatine kinase activity [Pre, 24 h after exercise (+24h), +48h, and 6 days after exercise (+6d)] were determined before (Pre) and after (+24h, +48h, +6d) exercise, with biopsies taken from the vastus lateralis of each leg at +48h for determination of muscle damage and/or inflammation. Plasma granulocyte counts increased for men and decreased for women at +48h (P < 0.05), and creatine kinase activity increased for both genders at +48h and +6d (P < 0.01). There were significantly greater areas of both focal (P < 0.001) and extensive (P < 0.01) damage in the Ex vs. Con leg for both genders, which was assessed by using toluidine blue staining. The number of leukocyte common antigen-positive cells/mm(2) tissue increased with exercise (P < 0.05), and men tended to show more in their Ex vs. Con leg compared with women (P = 0.052). Men had a greater total (Ex and Con legs) number of bcl-2-positive cells/mm(2) tissue vs. women (P < 0.05). Atrophic fibers with homogeneous bcl-2-positive staining were seen only in men (n = 3). We conclude that muscle damage is similar between genders, yet the inflammatory response is attenuated in women vs. men. Finally, exercise may stimulate the expression of proteins involved in apoptosis in skeletal muscle.

Pattern of muscle injuries and predictors of return-to-play duration among Malaysian athletes

“…It has been found that there are significantly fewer inflammatory cells (neutrophils and granulocytes) infiltrating the vastus lateralis muscle of female university students after a standardised pain-inducing eccentric exercise compared to males. (32) Infiltration of the muscle with leucocytes and macrophages is important for satellite cell activation and initiation of muscle regeneration. Therefore, the oestrogen-attenuating effects on leucocyte infiltration may delay important stages in muscle recovery.…”

Aspectos atuais sobre estresse oxidativo, exercícios físicos e suplementação

“…Post-injury pain induced by exercise frequently has its peak between 24 to 48 post-exercise hours. Muscular injury induced by performance of an eccentric exercises bout may be derived from connective tissues rupture ligated to adjacent myofibrils from the muscular cell itself, from the basal laminate adjacent to the plasmatic membrane, the plasmatic membrane of the muscular cell, the sarcomere, the plasmatic reticule, or even of a combination of these components (1)(2)(3)(4) . Muscular fibers injuries are usually evaluated by the determination of the reflux of cytosolic enzymes specific for blood circulation, combined with histological techniques or ultrastructural evaluation through electronic microscopy in order to evaluate the local effects.…”

“…The injury usually becomes more extensive during the next 48-72 post-exercise hours. The histological observation of the injured muscle may be characterized by the myofibrillar rupture, irregular structures of the Z lines, sarcolemma rupture, irregular location of organelles, increase of the mitochondrial density and the myofibrillar proteins and cytoskeleton content (3)(4) . The increase of cytosolic proteins in the circulation after exercise reflects the muscular injury.…”

“…The CK post-exercise muscular reflux peak is dependent on the type of exercise performed. Although a detectable increase in the activity immediately after exercise may occur, the peak of this enzyme is usually reached between 24 and 72 post-exercise hours (4)(5) . Tiidus and Ianuzzo (6) showed that both exercise intensity and duration independently affect the enzymatic seric activity and the muscular pain; however, intensity is the variable with the highest effect.…”

“…The consumption of adenosine triphosphate (ATP), the alteration in the calcium homeostasis and the ORS production have been shown in the injury and muscular necrosis etiology (1)(2)(3)(4)(5) (figure 1).…”