In vivo cardiac nano-imaging: A new technology for high-precision analyses of sarcomere dynamics in the heart.
The cardiac pump function is a result of a rise in intracellular Ca2+and the ensuing sarcomeric contractions [i.e., excitation-contraction (EC) coupling] in myocytes in various locations of the heart. In order to elucidate the heart's mechanical properties under various settings, cardiac imaging is widely performed in today's clinical as well as experimental cardiology by using echocardiogram, magnetic resonance imaging and computed tomography. However, because these common techniques detect local myocardial movements at a spatial resolution of ∼100 μm, our knowledge on the sub-cellular mechanisms of the physiology and pathophysiology of the heart in vivo is limited. This is because (1) EC coupling occurs in the μm partition in a myocyte and (2) cardiac sarcomeres generate active force upon a length change of ∼100 nm on a beat-to-beat basis. Recent advances in optical technologies have enabled measurements of intracellular Ca2+dynamics and sarcomere length displacements at high spatial and temporal resolution in the beating heart of living rodents. Future studies with these technologies are warranted to open a new era in cardiac research.
Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Sinjuku-ku, Tokyo 162-8480, Japan.
Togo
T
Shimozawa
Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
Erisa
E
Hirokawa
Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
Fuyu
F
Kobirumaki-Shimozawa
Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
Kotaro
K
Oyama
Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033, Japan.
Seine A
SA
Shintani
Department of Anesthesiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
Takako
T
Terui
Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
Yasuharu
Y
Kushida
Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
Seiichi
S
Tsukamoto
Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
Teruyuki
T
Fujii
Department of Physics, Faculty of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Shin'ichi
S
Ishiwata
Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan. Electronic address: noriof@jikei.ac.jp.
Norio
N
Fukuda
D000818:Animals; D002118:Calcium / Q000378:metabolism; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D057054:Molecular Imaging / Q000379:methods*; D036103:Nanotechnology / Q000379:methods*; D012518:Sarcomeres / Q000378:metabolism*
D002118:Calcium
Contractility; Muscle; Ventricular function