caa a22 4500 445373393 CHVBK 20180317142954.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s00540-011-1234-0 doi (NATIONALLICENCE)springer-10.1007/s00540-011-1234-0 Calcium-induced calcium release from the sarcoplasmic reticulum can be evaluated with a half-logistic function model in aequorin-injected cardiac muscles [Elektronische Daten] [Ju Mizuno, Kazuo Hanaoka, Mikiya Otsuji, Hideko Arita, Hidetoshi Sakamoto, Satoru Fukuda, Shigehito Sawamura] Purpose: Release of calcium (Ca2+) from the sarcoplasmic reticulum (SR) induced by Ca2+ influx through voltage-dependent sarcolemmal L-type Ca2+ channels (CICR) in cardiac muscle cells has been implicated as a potential target contributing to anesthetic-induced myocardial depression. In an earlier study, we found that (1) a half-logistic (h-L) function, which represents a half-curve of a sigmoid logistic function with a boundary at the inflection point, curve-fits the first half of the ascending phases of the isometric myocardial tension and isovolumic left ventricular (LV) pressure waveforms better than a mono-exponential (m-E) function and (2) the h-L time constants are useful as inotropic indices. We report here our investigation of the potential application of an h-L function to the analysis of the first half of the ascending phase of the Ca2+ transient curve (faCaT) that precedes and initiates myocardial contraction and the increase in LV pressure. Methods: Ca2+ transients (CaT) were measured using the Ca2+-sensitive photoprotein aequorin, which was microinjected into seven isolated rabbit right ventricular and 15 isolated mouse LV papillary muscles. The faCaT data from the beginning of twitch stimulation to the maximum of the first-order time derivative of Ca2+ concentration (dCa/dt max) was curve-fitted by the least-squares method using h-L and m-E function equations. Results: The mean correlation coefficient (r) values of the h-L and m-E curve-fits for the faCaTs were 0.9740 and 0.9654 (P<0.05) in the rabbit and 0.9895 and 0.9812 (P<0.0001) in the mouse. Conclusion: The h-L curves tracked the amplitudes and time courses of the faCaTs in cardiac muscles more accurately than m-E functions. Based on this result, we suggest that the h-L time constant may be a more reliable index than the m-E time constant for evaluating the rate of CICR from the SR in myocardial Ca2+ handling. The h-L approach may provide a more useful model for the study of CICR during the contraction process induced by anesthetic agents. Japanese Society of Anesthesiologists, 2011 Myocardial contraction nationallicence Calcium transient nationallicence Curve-fit nationallicence Time constant nationallicence Calcium handling nationallicence Mizuno Ju Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut Hanaoka Kazuo Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut Otsuji Mikiya Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut Arita Hideko Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut Sakamoto Hidetoshi Department of Anesthesiology and the Intensive Care Unit, Teikyo University School of Medicine, 2-11-1 Kaga, 173-8605, Itabashi-ku, Tokyo, Japan aut Fukuda Satoru Department of Anesthesiology and the Intensive Care Unit, Teikyo University School of Medicine, 2-11-1 Kaga, 173-8605, Itabashi-ku, Tokyo, Japan aut Sawamura Shigehito Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut Journal of Anesthesia Springer Japan 25/6(2011-12-01), 831-838 0913-8668 25:6<831 2011 25 540 https://doi.org/10.1007/s00540-011-1234-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00540-011-1234-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mizuno Ju Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut NATIONALLICENCE 700 1- Hanaoka Kazuo Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut NATIONALLICENCE 700 1- Otsuji Mikiya Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut NATIONALLICENCE 700 1- Arita Hideko Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut NATIONALLICENCE 700 1- Sakamoto Hidetoshi Department of Anesthesiology and the Intensive Care Unit, Teikyo University School of Medicine, 2-11-1 Kaga, 173-8605, Itabashi-ku, Tokyo, Japan aut NATIONALLICENCE 700 1- Fukuda Satoru Department of Anesthesiology and the Intensive Care Unit, Teikyo University School of Medicine, 2-11-1 Kaga, 173-8605, Itabashi-ku, Tokyo, Japan aut NATIONALLICENCE 700 1- Sawamura Shigehito Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, 113-8655, Bunkyo-ku, Tokyo, Japan aut NATIONALLICENCE 773 0- Journal of Anesthesia Springer Japan 25/6(2011-12-01), 831-838 0913-8668 25:6<831 2011 25 540 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer