Details

Autor(en) / Beteiligte

• Lieber, Samuel C
• Aubry, Nadine
• Pain, Jayashree
• Diaz, Gissela
• Kim, Song-Jung
• Vatner, Stephen F

Titel

Aging increases stiffness of cardiac myocytes measured by atomic force microscopy nanoindentation

Ist Teil von

• American journal of physiology. Heart and circulatory physiology, 2004-08, Vol.287 (2), p.H645-H651

Ort / Verlag

United States

Erscheinungsjahr

2004

Quelle

MEDLINE

Beschreibungen/Notizen

• 1 Cardiovascular Research Institute and the Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry of New Jersey–New Jersey Medical School, Newark, 07103; and 2 Department of Mechanical Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102 Submitted 15 June 2003 ; accepted in final form 16 March 2004 It is well established that the aging heart exhibits left ventricular (LV) diastolic dysfunction and changes in mechanical properties, which are thought to be due to alterations in the extracellular matrix. We tested the hypothesis that the mechanical properties of cardiac myocytes significantly change with aging, which could contribute to the global changes in LV diastolic dysfunction. We used atomic force microscopy (AFM), which determines cellular mechanical property changes at nanoscale resolution in myocytes, from young (4 mo) and old (30 mo) male Fischer 344 x Brown Norway F1 hybrid rats. A measure of stiffness, i.e., apparent elastic modulus, was determined by analyzing the relationship between AFM indentation force and depth with the classical infinitesimal strain theory and by modeling the AFM probe as a blunted conical indenter. This is the first study to demonstrate a significant increase ( P < 0.01) in the apparent elastic modulus of single, aging cardiac myocytes (from 35.1 ± 0.7, n = 53, to 42.5 ± 1.0 kPa, n = 58), supporting the novel concept that the mechanism mediating LV diastolic dysfunction in aging hearts resides, in part, at the level of the myocyte. cell mechanics; elastic modulus; heart; nanotechnology Address for reprint requests and other correspondence: S. F. Vatner, Dept. of Cell Biology and Molecular Medicine, MSB G-609, Univ. of Medicine and Dentistry of New Jersey–New Jersey Medical School, PO Box 1709, Newark, NJ 07101-1709 (E-mail: vatnersf{at}umdnj.edu ).