Half-Logistic Function Model for First Half of Descending Phase of Cardiomyocyte Cytoplasmic Ca2+ Concentration (Ca2+i)-Time Curve (CaTCIII) in Isolated Aequorin-Injected Mouse Left Ventricular Papillary Muscle

摘要

Background Myocardial contraction and relaxation are regulated by increases and decreases in cytoplasmic calcium concentration ([Ca²⁺]i). In previous studies, we found that a half-logistic (h-L) function, which represents a half-curve of a symmetrical sigmoid logistic function with a boundary at the inflection point, curve-fits the first half of the ascending phase and the second half of the descending phase of the [Ca²⁺]i transient curve better than a mono-exponential (m-E) function. In the present study, we investigated the potential application of an h-L function to analyse the first half of the descending phase of CaTC (CaTCIII).