Key result
Adult hypertrophy is linked to greater cardiomyocyte polyploidy while the DNA-to-protein ratio remains stable.
Why the study?
The changes in myocardial DNA content and DNA/protein ratio during human heart maturation and hypertrophy were not fully characterized.
Observational
The stability of the DNA/protein ratio in adult cardiac hypertrophy is driven by a concomitant increase in both DNA and protein, associated with increased cellular polyploidy.
Human heart muscle cells are diploid at birth. In agreement with other data, they become tetraploid in normal adults and develop greater polyploidy in adult hypertrophy. Some cases of infantile hypertrophy appear to have mostly tetraploid nuclei. In keeping with the enlargement of muscle cells which occurs during growth, the DNA/protein ratio is high at birth, progressively decreasing until adulthood, after which it does not change in hypertrophied hearts except in clinically unusual conditions. This stability of the DNA/protein ratio in hypertrophy thus appears due to a concomitant increase in DNA and protein in the muscle cells.
No takes yet. Share an insight, caveat, or question.
Eisenstein et al. (1970) conducted an observational in Myocardial hypertrophy. Maturation and hypertrophy vs. Normal development was evaluated on DNA/protein ratio and ploidy. Human heart muscle cells become tetraploid in normal adults and develop greater polyploidy in adult hypertrophy, while the DNA/protein ratio remains stable due to concomitant increases in both.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: