caa a22 4500 47711282X CHVBK 20180405111614.0 cr unu---uuuuu 170330e19960701xx s 000 0 eng 10.1007/BF02559989 doi (NATIONALLICENCE)springer-10.1007/BF02559989 Logistic character of myocardial twitch force curve: Simulation [Elektronische Daten] [Taisuke Sakamoto, Hiromi Matsubara, Yoshiki Hata, Juichiro Shimizu, Junichi Araki, Miyako Takaki, Hiroyuki Suga] Summary: We found that the isovolumic pressure-time curve of the canine left ventricle closely fitted the difference of two logistic function curves and that the isovolumic relaxation-pressure curve segment was more reliably characterized by a logistic time constant than by the conventional exponential time constant. We therefore hypothesized that the calcium (Ca) transient and the Ca-troponin (Tn) binding and crossbridge (CB) kinetics underlay the logistic character of the ventricular isovolumic pressure curve. We tested this hypothesis with a computer simulation of a simple Ca and CB kinetics model of myocardial isometric twitch force development. We assumed the isometric force curve (F) to be proportional to the instantaneous number of attached CBs that was theoretically given as the difference between the cumulative CB attachment and detachment curves. We radically changed the Ca transient, Ca-Tn binding, and CB kinetic parameters. We always found that both the cumulative CB attachment and detachment curves closely fitted logistic functions. The difference curve of these two best-fit logistic functions closely fitted the theoretical F curve with certain combinations of the Ca transient, the Ca-Tn binding, and the CB kinetic parameters. These results seem to support our hypothesis. Springer-Verlag, 1996 Logistic function nationallicence Myocardial force nationallicence Calcium kinetics nationallicence Calcium transient nationallicence Curve fitting nationallicence Sakamoto Taisuke Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut Matsubara Hiromi Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut Hata Yoshiki Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut Shimizu Juichiro Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut Araki Junichi Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut Takaki Miyako Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut Suga Hiroyuki Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut Heart and Vessels Springer-Verlag 11/4(1996-07-01), 171-179 0910-8327 11:4<171 1996 11 380 https://doi.org/10.1007/BF02559989 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02559989 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sakamoto Taisuke Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut NATIONALLICENCE 700 1- Matsubara Hiromi Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut NATIONALLICENCE 700 1- Hata Yoshiki Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut NATIONALLICENCE 700 1- Shimizu Juichiro Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut NATIONALLICENCE 700 1- Araki Junichi Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut NATIONALLICENCE 700 1- Takaki Miyako Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut NATIONALLICENCE 700 1- Suga Hiroyuki Department of Physiology II, Okayama University Medical School, 2-5-1 Shikata-cho, 700, Okayama, Japan aut NATIONALLICENCE 773 0- Heart and Vessels Springer-Verlag 11/4(1996-07-01), 171-179 0910-8327 11:4<171 1996 11 380 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer