Cardiac Performance, Dr. D. Penney
Changes in Gene Expression in Cardiac Overload:
Quantitative changes:
Coordinated increase in protein (myosin, actin, myoglobin, Ca++ channels, mitochondria, surface membrane) and RNA (m, r and t) synthesis.
Regulated at a transcriptional and at the translational level.
Adaptational, because it multiplies contractile units and decreases wall stress.
Qualitative changes:
Several shifts in isoforms (myosin, creatine kinase, actin, tropomyosin, LDH, Na+-K+, ATPase, and SR protein).
Due to an isogene change in expression (myosin).
Adaptational because it decreases Vmax. and improves heat production.
Last changed 03/11/98
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