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Age‐Related Cardiac Sarcopenia
Author(s) -
Lin Jing,
Lopez Elizabeth,
Van Remmen Holly,
Freeman Gregory,
Lindsey Merry L
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a1310-a
Subject(s) - sarcopenia , fibrosis , medicine , myocyte , ejection fraction , endocrinology , cardiac fibrosis , periodic acid–schiff stain , muscle hypertrophy , senescence , glycogen , heart failure , cardiology , immunohistochemistry
Background: In skeletal muscle, age‐related sarcopenia is a well‐characterized event. Sarcopenia has also been documented in aortic smooth muscle cells. Whether cardiac sarcopenia occurs with aging, however, has not been previously demonstrated. Accordingly, we evaluated adult (8.6¡À0.8 months; n=15) and senescent (31.0¡À0.6 months; n=14) mice for indications of cardiac sarcopenia using echocardiography, histological and biochemical assessments. Methods and Results: End diastolic dimension increased from 3.76¡À0.01 mm in adult mice to 4.26¡À0.12 mm in senescent mice (p<0.05). Ejection fraction decreased from 70¡À1% in adult to 57¡À3% in senescent mice (p<0.05), indicating reduced contractile performance. Myocyte cell numbers, measured as a percentage of nuclei, decreased from 6.3¡À0.4% in adult to 4.9¡À0.3% in senescent group (p<0.05). Interstitial fibrosis was punctate but significantly increased in the senescent mice, indicative of reparative fibrosis. In the senescent mice, oil red o staining revealed increased intracellular lipid accumulation, while periodic acid Schiff staining showed a concomitant decrease in glycogen stores. Conclusion: This is the first report to document age‐related cardiac sarcopenia in mice. The decrease in cell numbers, increase in individual myocyte hypertrophy and increased reparative fibrosis may combine to alter left ventricular function. Cardiac sarcopenia may explain, in part, why elderly patients respond poorly to cardiovascular events.