Creatine kinase, myosin heavy chains and magnetic resonance imaging after eccentric exercise

Abstract

The aim of this study was to examine the relationship between myosin heavy chain (MHC) release as a specific marker of slow-twitch muscle fibre breakdown and magnetic resonance imaging (MRI) of skeletal muscle injury after eccentric exercise. The effects of a single series of 70 high-intensity eccentric contractions of the quadriceps femoris muscle group (single leg) on plasma concentrations of creatine kinase and MHC fragments were assessed in 10 young male sport education trainees before and 1 and 4 days after exercise. To visualize muscle injury, MRI of the loaded thigh was performed before and 4 days after the eccentric exercise. All participants recorded an increase (P < 0.05) in creatine kinase after exercise. In five participants, T2 signal intensity was unchanged post-exercise compared with pre-exercise and MHC plasma concentration was normal; however, they showed an increase (P < 0.05) in creatine kinase after exercise. For the remaining five participants, there was an increase in T2 signal intensity of the loaded vastus intermedius and vastus lateralis. These changes in MRI were accompanied by an increase in MHC plasma concentration (P< 0.01) as well as an increase in creatine kinase (P < 0.01). We suggest that changes in MRI T, signal intensity after muscle damage induced by eccentric exercise are closely related to damage to structurally bound contractile filaments of some muscle fibres. Additionally, MHC plasma release indicates that this damage affects not only fast-twitch fibres but also some slow-twitch fibres.

Is isometric strength loss immediately after eccentric exercise related to changes in indirect markers of muscle damage?

“…In addition to the prolonged loss of force-generating capacity, eccentric exercise also results in several other phenomena such as delayed-onset muscle soreness (DOMS), muscle contracture, decreased range of motion (ROM), swelling, increase of muscle proteins in the blood (e.g., creatine kinase (CK) and myoglobin), and abnormalities in magnetic resonance and ultrasound images (Clarkson et al 1992;Howell et al 1993;Nosaka and Clarkson 1996b;Sorichter et al 2001). These other markers are often used as indices of muscle damage; however, neither the underlying physiological processes leading to the observed changes nor the relationship between these phenomena and strength loss are clearly understood.…”

“…evidence that increases in CIR after eccentric exercise are a consequence of tissue swelling associated with the delayed inflammatory response (Howell et al 1993;Chleboun et al 1998), and that increases in plasma CK activity are indicative of myofibre necrosis (McNeil and Khakee 1992;Nosaka and Clarkson 1996b;Sorichter et al 2001). Our findings support these concepts, in that MVC-D4 showed higher correlation values with peak plasma CK activity (r = -0.75), as well as with CIR 4 d after exercise (r = -0.64), than did MVC-post or MVC-D1 (Table 3).…”

Effects of Strenuous Exercise with Eccentric Muscle Contraction: Physiological and Functional Aspects of Human Skeletal Muscle

“…In fact, several studies using T 2 W imaging have revealed delayed muscle edema that was signiˆcantly correlated with increased serum creatine kinase value after eccentric exercise. 6,9,10 Considering the signiˆcant correlation between the T 2 values and water diŠusion coe‹cients of exercised muscles, 11,22 increased water level within muscle would strongly contribute to the delayed ADC elevation in the MG; edema creates larger extracellular space with fewer membrane barriers, which allows greater unrestricted water motion. The disruptedˆber structure in itself should also lead to increased water diŠusion because water diŠusion is mostly restricted parallel to muscleˆber orientation.…”

“…[5][6][7][8] Several studies have used magnetic resonance (MR) T 2 -weighted (T 2 W) images to evaluate muscle damage induced by eccentric exercise. 6,9,10 One damage-based pathophysiological change revealed by T 2 W imaging is delayed muscle edema, which frequently occurs a few days following eccentric exercise. However, the micromovement of water molecules within damaged muscle has not been su‹-ciently investigated in the recovery process from eccentric exercise.…”

Efeito do exercício excêntrico sobre as propriedades mecânicas do músculo e índices de aptidão aeróbia

“…Contudo, outras consequências também são relacionadas com exercícios excêntricos: aumento específico da atividade de enzimas musculares como creatina quinase (CK) e lactato desidrogenase (LDH) (BROWN et al, 1999); aumento da pressão intramuscular inflamação;edema (CLARKSON;SAYERS, 1999); inchaço (SORICHTER et al, 2001); desconforto no local da lesão e pontos de inserção do tendão (MACINTYRE et al, 1995) e mudança na reposta aferente originada do fuso muscular, órgão tendinoso de Golgi (OTG) e grupos III e IV de nervos aferentes (KOMI, 2000). Em particular, como resultado desta última resposta aferente, há uma substancial diminuição no reflexo de alongamento e redução da regulação da rigidez do músculo e articulação (citado na literatura como muscle and joint stiffness) e redução no desempenho muscular .…”