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

Document Type

Article

Publication Date

8-1-2004

Abstract

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.

Identifier

3242701396 (Scopus)

Publication Title

American Journal of Physiology Heart and Circulatory Physiology

External Full Text Location

https://doi.org/10.1152/ajpheart.00564.2003

ISSN

03636135

PubMed ID

15044193

First Page

H645

Last Page

H651

Issue

2 56-2

Volume

287

Grant

P01HL059139

Fund Ref

National Heart, Lung, and Blood Institute

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