Abstract
We compared myocardial mechanics and myosin isozymes of right and left ventricular papillary muscles from adult (6 to 8 month old) male rats. Analysis of force velocity relations indicate that right ventricular papillary muscles contract more rapidly than left at light loads (2.68±0.13 vs 2.18±0.07 muscle lengths/s measured 75 ms following stimulation, at 0.5 g/mm2; P<0.01). Right ventricular papillary muscles had significantly more of the α heavy chain containing V1 myosin isozyme and less of the V3 containing β heavy chain myosin isozyme than left ventricular preparations (P<0.05). Papillary muscle and ventricular free wall myosin isozyme distribution were not significantly different within their respective chambers. The presence of a relatively larger proportion of the α heavy chain containing myosin isozyme (V1) in right ventricle papillary muscles relative to left correlated with the more rapid velocities of shortening seen in right ventricular papillary muscles (r=0.60; P<0.01).
Original language | English (US) |
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Pages (from-to) | 433-440 |
Number of pages | 8 |
Journal | Journal of Molecular and Cellular Cardiology |
Volume | 19 |
Issue number | 5 |
DOIs | |
State | Published - 1987 |
Externally published | Yes |
Keywords
- Myocardial mechanics
- Myosin isozymes
- Papillary muscle
- Right and left ventricle
ASJC Scopus subject areas
- Molecular Biology
- Cardiology and Cardiovascular Medicine