Related Experiment Videos
Alterations in myocardial collagen content affect rat papillary muscle function
L S Matsubara1, B B Matsubara, M P Okoshi
1Departamento de Clínica Médica, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista, Botucatu, São Paulo, Brazil 18618-000. lmatsu@fmb.unesp.br
American Journal of Physiology. Heart and Circulatory Physiology
|September 29, 2000
Summary
Altered myocardial collagen levels impact rat heart muscle function. Decreased collagen leads to hypertrophy and increased active stiffness, while increased collagen causes diastolic dysfunction.
Area of Science:
- Cardiovascular Physiology
- Cardiac Remodeling
- Biochemistry
Background:
- Myocardial collagen volume fraction (CVF) and hydroxyproline concentration are key determinants of cardiac structure and function.
- Understanding collagen's role is crucial for diagnosing and treating heart conditions.
Purpose of the Study:
- To investigate the effects of altered myocardial collagen content on rat papillary muscle function.
- To correlate collagen levels with changes in active and passive stiffness, and myocyte size.
Main Methods:
- Induction of collagen excess (RHTR rats) and degradation (GSSG rats) in rat models.
- Measurement of collagen volume fraction (CVF) and hydroxyproline concentration.
- Assessment of active stiffness (AS), passive tension-length curves, and myocyte cross-sectional area (MA).
Main Results:
- GSSG rats (decreased collagen) showed increased AS and MA compared to controls.
- Both GSSG and RHTR groups exhibited altered passive stiffness.
- Increased collagen concentration was linked to myocardial diastolic dysfunction without affecting systolic function.
Conclusions:
- Decreased myocardial collagen content is associated with myocyte hypertrophy, reduced passive stiffness, and increased active stiffness.
- Increased collagen concentration contributes to myocardial diastolic dysfunction.