Nano-imaging of the beating mouse heart in vivo: Importance of sarcomere dynamics, as opposed to sarcomere length per se, in the regulation of cardiac function

Fuyu Kobirumaki-Shimozawa, Kotaro Oyama, Togo Shimozawa, Akari Mizuno, Takashi Ohki, Takako Terui, Susumu Minamisawa, Shin'ichi Ishiwata, Norio Fukuda

    Research output: Contribution to journalArticle

    22 Citations (Scopus)

    Abstract

    Sarcomeric contraction in cardiomyocytes serves as the basis for the heart's pump functions in mammals. Although it plays a critical role in the circulatory system, myocardial sarcomere length (SL) change has not been directly measured in vivo under physiological conditions because of technical difficulties. In this study, we developed a high speed (100-frames per second), high resolution (20-nm) imaging system for myocardial sarcomeres in living mice. Using this system, we conducted three-dimensional analysis of sarcomere dynamics in left ventricular myocytes during the cardiac cycle, simultaneously with electrocardiogram and left ventricular pressure measurements. We found that (a) the working range of SL was on the shorter end of the resting distribution, and (b) the left ventricular- developed pressure was positively correlated with the SL change between diastole and systole. The present findings provide the first direct evidence for the tight coupling of sarcomere dynamics and ventricular pump functions in the physiology of the heart.

    Original languageEnglish
    Pages (from-to)53-62
    Number of pages10
    JournalJournal of General Physiology
    Volume147
    Issue number1
    DOIs
    Publication statusPublished - 2016

    ASJC Scopus subject areas

    • Physiology

    Fingerprint Dive into the research topics of 'Nano-imaging of the beating mouse heart in vivo: Importance of sarcomere dynamics, as opposed to sarcomere length per se, in the regulation of cardiac function'. Together they form a unique fingerprint.

  • Cite this

    Kobirumaki-Shimozawa, F., Oyama, K., Shimozawa, T., Mizuno, A., Ohki, T., Terui, T., Minamisawa, S., Ishiwata, S., & Fukuda, N. (2016). Nano-imaging of the beating mouse heart in vivo: Importance of sarcomere dynamics, as opposed to sarcomere length per se, in the regulation of cardiac function. Journal of General Physiology, 147(1), 53-62. https://doi.org/10.1085/jgp.201511484