Accepted_test

Features of the contractile characteristics of single cardiomyocytes in the myocardial sleeves of the pulmonary veins of guinea pigs
by Xenia Butova | Tatiana Myachina | Raisa Simonova | Anastasia Kochurova | Anastasia Khokhlova | Galina Kopylova | Institute of Immunology and Physiology | Institute of Immunology and Physiology | Institute of Immunology and Physiology | Institute of Immunology and Physiology | Institute of Immunology and Physiology | Institute of Immunology and Physiology
Abstract ID: 365
Event: BGRS-abstracts
Sections: [Sym 9] Section “Molecular Pathology, Diagnostics, and Therapeutics”

Myocardial sleeves of the pulmonary veins (PV) extending from the left atrium (LA) are the major source of ectopic activity causing atrial arrhythmias. The mechanical activity of cardiomyocytes impacts cardiac excitation-contraction coupling, however, the mechanical function of PV cardiomyocytes is still poorly understood. We compared the characteristics of the actin-myosin interaction and sarcomere length dynamics in single cardiomyocytes in PV and LA of the guinea pig heart. We found that the functional properties of myosin from PV and LA are not different, while the phosphorylation levels of sarcomeric proteins in PV and LA differ. The characteristics of sarcomere shortening-relengthening of PV and LA cardiomyocytes do not differ, while PV cardiomyocytes are longer and thinner than LA cardiomyocytes. Unlike LA, in PV the amplitude of sarcomere shortening does not correlate with cardiomyocyte length. It can be assumed that an absence of such correlation together with the electrophysiological properties of the PV myocardium, might contribute to the occurrence and development of atrial fibrillation.