Cytokines and cell adhesion molecules associated with high-intensity eccentric exercise

Unaccustomed, eccentrically biased exercise induces trauma to muscle and/or connective tissue. Tissue damage activates an acute inflammatory response. Inflammation requires the effective interaction of different physiological and biological systems. Much of this is coordinated by the de novo synthes is of families of protein molecules, cytokines. The purpose of the present paper was to determine changes in blood levels of various cytokines in resp onse to exercise-induced muscle damage that was effected using high-intensi ty eccentric exercise. Six healthy, untrained, college-age male subjects we re required to perform the eccentric phase of a bench press and a leg curl (4 sets, 12 repetitions/set) at an intensity equivalent to 100% of their pr eviously determined one-repetition maximum. Samples of blood were drawn at the following times: before exercise and 1.5, 6, 12, 24, 48, 72, 96, 120, a nd 144 h after exercise. These samples were analyzed for interleukins (IL): IL-I beta, IL-6, and IL-10; tumor necrosis factor-a; colony stimulating fa ctors (CSF): granulocyte-CSF, macrophage-CSF, and GM-CSF; for cell adhesion molecules (CAM): P- and E-selectin, and intercellular cell adhesion molecu le (ICAM-1), and vascular cell adhesion molecule (VCAM-1). Results were ana lyzed using a repeated-measures analysis of variance (P = 0.05). Compared t o baseline values, IL-IP was reduced (P = 0.03) at 6, 24, and 96-144 h afte r exercise; IL-6 was elevated (P = 0.01) at 12, 24, and 72 h after exercise ; IL-IO was elevated (P = 0.009) between 72 and 144 h after exercise; M-CSF was elevated (P = 0.005) at 12 and 48-144 h after exercise; and P-selectin was reduced (P = 0.01) between 24 and 144 h after exercise. It is conclude d that when high-intensity eccentric exercise is compared to strenuous endu rance exercise, post-exercise changes in cytokines do occur, but they are g enerally of a smaller magnitude, and occur at a later time period after the termination of exercise.