title: Cardiac myocytes' dynamic contractile behavior differs depending on heart segment.
abstract: Cardiac myocytes originating from different parts of the heart exhibit varying morphology and ultrastructure. However, the difference in their dynamic behavior is unclear. We examined the contraction of cardiac myocytes originating from the apex, ventricle, and atrium, and found that their dynamic behavior, such as amplitude and frequency of contraction, differs depending on the heart segment of origin. Using video microscopy and high-precision image correlation, we found that: (1) apex myocytes exhibited the highest contraction rate (∼17 beats/min); (2) ventricular myocytes exhibited the highest contraction amplitude (∼5.2 micron); and (3) as myocyte contraction synchronized, their frequency did not change significantly, but the amplitude of contraction increased in apex and ventricular myocytes. In addition, as myocyte cultures mature they formed contractile filaments, further emphasizing the difference in myocyte dynamics is persistent. These results suggest that the dynamic behavior (in addition to static properties) of myocytes is dependent on their segment of origin.
authors.affiliation: Department of Mechanical Science and Engineering, University of Illinois at Urbana Champaign-Illinois, 142 MEB MC: 244, 1206 W. Green Street, Urbana, Illinois 61801, USA. emerson.jose.desouza@gmail.com
authors.forename: Emerson J
authors.initials: EJ
authors.lastname: De Souza
authors.forename: Wylie
authors.initials: W
authors.lastname: Ahmed
authors.forename: Vincent
authors.initials: V
authors.lastname: Chan
authors.forename: Rashid
authors.initials: R
authors.lastname: Bashir
authors.forename: Taher
authors.initials: T
authors.lastname: Saif
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D005260:Female; D006325:Heart Atria / Q000166:cytology*; D006352:Heart Ventricles / Q000166:cytology*; D018715:Microscopy, Video; D009200:Myocardial Contraction / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000145:classification / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012518:Sarcomeres / Q000502:physiology / Q000648:ultrastructure