Differences in the spatial distribution of actin in the left and right ventricles of functioning rabbit hearts

J. Nagwekar, D. Duggal, R. Rich, Rafal Fudala, Ignacy Gryczynski, Sangram Limbaji Raut, Zygmunt Gryczynski, Julian Borejdo

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We examined the effect of the differences in spatial arrangement of actin in contracting muscles from the left (LV) and right (RV) ventricles of rabbit heart. Spatial arrangement is a fundamental property of muscle because it reflects the interaction of individual actin molecules with myosin cross-bridges. Macroscopic parameters of contraction, such as maximum tension, speed of shortening or ATPase activity, are unlikely to reveal differences between the ventricles because they are made on whole organs containing trillions of actin and myosin molecules. Averaging the data collected from such a large assembly is likely to conceal small differences. To eliminate complications arising from the differences in the basic myocardial architecture and fiber structures of the ventricles, and to ensure that the molecular crowding influences contraction in the same way as under the in-vivo conditions, we collected data from isolated myofibrils ex-vivo. Control anisotropy experiments revealed that the orientation of actin reflected the orientation of myosin cross-bridges. The results showed that the changes in the distribution of actin induced by the interaction of actin filaments with myosin heads were demonstrated only in LVs, not in RVs. This suggests that both ventricles interact differently with myosin cross-bridges. We think that the stress induced in the thin filaments of LV causes loosening of bonds between actin monomers which leads to greater mobility of actin monomers.

Original languageEnglish
Pages (from-to)1-8
Number of pages8
JournalMedical Photonics
Volume27
DOIs
StatePublished - 1 Mar 2018

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Heart Ventricles
Actins
Myosins
Rabbits
Muscles
Crowding
Myofibrils
Anisotropy
Actin Cytoskeleton
Adenosine Triphosphatases

Keywords

  • Actin orientation
  • Fluorescence polarization
  • Heart ventricles

Cite this

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title = "Differences in the spatial distribution of actin in the left and right ventricles of functioning rabbit hearts",
abstract = "We examined the effect of the differences in spatial arrangement of actin in contracting muscles from the left (LV) and right (RV) ventricles of rabbit heart. Spatial arrangement is a fundamental property of muscle because it reflects the interaction of individual actin molecules with myosin cross-bridges. Macroscopic parameters of contraction, such as maximum tension, speed of shortening or ATPase activity, are unlikely to reveal differences between the ventricles because they are made on whole organs containing trillions of actin and myosin molecules. Averaging the data collected from such a large assembly is likely to conceal small differences. To eliminate complications arising from the differences in the basic myocardial architecture and fiber structures of the ventricles, and to ensure that the molecular crowding influences contraction in the same way as under the in-vivo conditions, we collected data from isolated myofibrils ex-vivo. Control anisotropy experiments revealed that the orientation of actin reflected the orientation of myosin cross-bridges. The results showed that the changes in the distribution of actin induced by the interaction of actin filaments with myosin heads were demonstrated only in LVs, not in RVs. This suggests that both ventricles interact differently with myosin cross-bridges. We think that the stress induced in the thin filaments of LV causes loosening of bonds between actin monomers which leads to greater mobility of actin monomers.",
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Differences in the spatial distribution of actin in the left and right ventricles of functioning rabbit hearts. / Nagwekar, J.; Duggal, D.; Rich, R.; Fudala, Rafal; Gryczynski, Ignacy; Raut, Sangram Limbaji; Gryczynski, Zygmunt; Borejdo, Julian.

In: Medical Photonics, Vol. 27, 01.03.2018, p. 1-8.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Differences in the spatial distribution of actin in the left and right ventricles of functioning rabbit hearts

AU - Nagwekar, J.

AU - Duggal, D.

AU - Rich, R.

AU - Fudala, Rafal

AU - Gryczynski, Ignacy

AU - Raut, Sangram Limbaji

AU - Gryczynski, Zygmunt

AU - Borejdo, Julian

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