Protein kinase C isozyme-specific modulation of cyclic AMP-dependent phosphodiesterase in hypertrophic

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Updated: Oct 14, 2026

Isolation, Culture, and Functional Characterization of Adult Mouse Cardiomyoctyes
12:49

Isolation, Culture, and Functional Characterization of Adult Mouse Cardiomyoctyes

Published on: September 24, 2013

J J Cai1, H C Lee

  • 1Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242, USA.

Molecular Pharmacology
|January 1, 1996
PubMed

Insights

Protein kinase C (PKC) isozymes, particularly PKC alpha, are elevated in hypertrophic cardiomyopathy (HCM) hearts. This PKC alpha isozyme specifically mediates the interaction between PKC and phosphodiesterase (PDE) in HCM.

Area of Science:

  • Cardiology
  • Molecular Biology
  • Biochemistry

Background:

  • Protein kinase C (PKC) activity is elevated in hypertrophic cardiomyopathic (HCM) hamster hearts.
  • PKC activation stimulates cAMP-dependent phosphodiesterase (PDE) activity in HCM.

Purpose of the Study:

  • To determine the composition of PKC isozymes in control and HCM hearts.
  • To identify the specific PKC isozyme responsible for modulating PDE activity in HCM hearts.

Main Methods:

  • Quantitative autoradiographic techniques with isozyme-specific antibodies.
  • Measurement of PKC enzymatic activity in membrane and cytosol fractions.
  • Immunoprecipitation assays to assess individual PKC isozyme contributions.

Main Results:

  • PKC alpha, epsilon, and zeta isozymes are expressed in both control and HCM hearts.
  • Elevated levels of specific PKC isozymes (cytosolic PKC alpha and epsilon, membrane PKC zeta) were observed in HCM hearts.
  • PKC alpha, but not epsilon or zeta, was identified as the specific isozyme mediating PKC-enhanced PDE activity in HCM.

Conclusions:

  • Hypertrophic cardiomyopathy is characterized by increased quantitative expression of specific PKC isozymes.
  • The cross-talk between PKC and PDE in HCM hearts is specifically mediated by the PKC alpha isozyme.

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