Brumen Milan, Fajmut Aleš, Dobovišek Andrej, Roux Etienne
Medical Faculty, University of Maribor, Slomškov trg 15, Maribor, Slovenia ; Department of Physics, University of Maribor, Koroška 160, Maribor, Slovenia ; Jozef Stefan Institute, Jamova 39, Ljubljana, Slovenia.
J Biol Phys. 2005 Dec;31(3-4):515-24. doi: 10.1007/s10867-005-2409-4.
The action of different agonists such as acetylcholine on the membrane of airway smooth muscle cells may induce cytosolic Ca(2+) oscillations which can be a part of the Ca(2+) signalling pathway, eventually leading to cell contraction. The aim of the present study is to present a mathematical model of the possible effect of the initial Ca(2+) distribution within the cell on the form and frequency of induced Ca(2+) oscillations. It takes into account intracellular Ca(2+) stores such as sarcoplasmic reticulum and cytosolic proteins as well as Ca(2+) exchange across the plasma membrane. We are able to demonstrate a closer agreement of model predictions with observed Ca(2+) traces for a significantly wider range of parameter values, as was previously reported. We show also that the total cellular Ca(2+) content is an important system parameter especially because of the content in sarcoplasmic reticulum. At a total Ca(2+) increase of about 20%, the oscillation frequency increases by 25%; also, damped oscillations become sustained. Cases are indicated in which such a situation could occur.
不同激动剂（如乙酰胆碱）作用于气道平滑肌细胞膜可能会诱导胞质Ca(2+)振荡，这可能是Ca(2+)信号通路的一部分，最终导致细胞收缩。本研究的目的是提出一个数学模型，以探讨细胞内初始Ca(2+)分布对诱导的Ca(2+)振荡的形式和频率可能产生的影响。该模型考虑了细胞内Ca(2+)储存（如肌浆网和胞质蛋白）以及跨质膜的Ca(2+)交换。与之前的报道一样，我们能够证明在更广泛的参数值范围内，模型预测与观察到的Ca(2+)轨迹更吻合。我们还表明，细胞内总Ca(2+)含量是一个重要的系统参数，特别是由于肌浆网中的含量。当总Ca(2+)增加约20%时，振荡频率增加25%；此外，阻尼振荡会变为持续振荡。文中指出了可能出现这种情况的案例。
