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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