A single bout of eccentric exercise increases HSP27 and HSC/HSP70 in human skeletal muscle

Changes in heat shock proteins (HSPs), HSP27 and HSC/HSP70 were characterized in human biceps brachii muscle following damaging high-force eccentric exercise. Male and female volunteers performed a maximal eccentric resistance exercise with the elbow flexor muscles of the non-dominant arm known to be sufficient to cause substantial muscle damage. Protein extracts of biopsy tissue samples taken 48 h post-exercise were immunoblotted for HSC/HSP70 and HSP27. Densitometric analysis demonstrated that these proteins increased significantly (P < 0.01) in the damaged biceps brachii relative to the control arm. The HSC/HSP70 increased 1064% in the exercised sample while HSP27 increased by 234%. Although the literature reports a muscular heat shock response following aerobic, oxidative exercise, this is the first documentation of increases in protein expression of both HSC/HSP70 and HSP27 in human skeletal muscle in response to a single bout of resistance exercise.