Ar nold Koller, Wolfgang Schobersberger
E x t r e m e k ö r p e r l i c h e B e lastungen: Vo m M u s k e l k a t e r b i s z u m „ H er zmuskelkater“ Extreme Physical Exercise: Skeletal Muscle and Heart Muscle Injuries
SUMMARY Disruption of proteins within the myofiber after unaccustomed eccentric exercise (postexercise release of skeletal troponin and myosin heavy chain fragments has been reported) is hypothesized to induce delayed onset of muscle soreness and to be associated with an activation of satellite cells (stem cells). Similarly, the increase in cardiac troponin after strenuous endurance exercise is suggested to be due to the true breakdown of the cardiomyocyte, not to the cytosolic release of the biomarker, as confirmed by histology and cardiac magnetic resonance imaging. Moreover, the human heart contains stem cells capable of generating cardiomyocytes. At this time, there is not enough evidence to implicate strenuous endurance exercise in the development of a dangerous substrate for coronary events in apparently healthy subjects. The true breakdown of the cardiomyocyte has been proposed either as pathognomic of cardiac necrosis or might reflect part of a remodeling process. Interestingly, completion of a marathon is associated with correlative biochemical and echocardiographic evidence of cardiac dysfunction and injury, and the risk is increased in those participants with less training. Keywords: delayed onset of muscle soreness, cardiac troponin, cardiac stem cell, cardiac magnetic resonace imaging
ZUSAMMENFASSUNG Untersuchungen zeigen, dass vor allem nach exzentrischen Belastungen Zerreissungen der Sarkomere auftreten, die sich als Muskelkater äußern. Proteine der Sarkomere (z. B. Myosinschwerketten, Troponine) können nach diesen Belastungen im Blut nachgewiesen werden. Den Satellitenzellen, den Stammzellen der Skelettmuskeln, wird bei den 277
