The Effects of Stretch on [Ca2+]i Decay in Isolated Rat Ventricular Cardiomyocytes

Lookin O.N., Kuznetsov D.A., Protsenko Y.L.

Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Yekaterinburg, Russian Federation

Abstract. The length-dependent effects on the kinetics of [Ca2+]i, e.g. a brief slowing of the monotonous decay of [Ca2+]i («bump»), are well documented in rat cardiac muscle. We aimed to establish these effects on the level of isolated rat ventricular cardiomyocytes. Three groups of measurements were established: i) no length-induced effects, ii) lengthening progressively slows down [Ca2+]i decay at the initial and late phases, iii) lengthening accelerates the initial decay but decelerates the late decay of [Ca2+]i. The second group occupies ~80% of total number of measurements including those where a «bump» was observed in stretched cell. «Bump» is typical for rat cardiac muscle and is thought to be associated with the length-dependent regulation of interaction between troponin C and Ca2+. We used cardiomyocytes isolated from different layers or regions of ventricular wall which may account for the diversity of the length-dependent effects on [Ca2+]i decay.

Keywords: cardiomyocyte, [Ca2+]i, stretch/length

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Authors
Lookin Oleg N., o.lookin@iip.uran.ru
Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences
PhD; senior research fellow
Russian Federation, 620049, Yekaterinburg, Pervomayskaya st., 106

Kuznetsov Daniil A., virus_x@mail.ru
junior research fellow

Protsenko Yuri L., y.protsenko@iip.uran.ru
MD; head research fellow