Length-Dependent Modulation of Cardiac Muscle Contractility in Normoxia, Hypoxia, and Acidosis: Possible Implications for Ischemia
The results discussed in this chapter suggest that the stretch-dependent increase in cardiac contraction is inhibited during hypoxia and modulated during acidosis. In ischemia, both hypoxia and acidosis occur simultaneously, so the length-dependent changes in cardiac contractility during ischemia would be a function of the changes in both conditions. The increase in cardiac contractility observed following muscle stretch might be inhibited during ischemia, possibly by altered Ca2+ handling and a decreased Ca2+sensitivity of the myofilaments. Thus, the contractile changes in the response to stretch observed in the present study during hypoxia and acidosis may modulate the contractile response of cardiac muscle to ischemia.
KeywordsCardiac Muscle Slow Phase Slow Increase Muscle Length Sarcomere Length
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