SIGNATURE WORK
CONFERENCE & EXHIBITION 2022

The regulation of cellular activities and maintaining of homeostasis highly rely on the intracellular calcium dynamics tightly organized by multiple cellular organelles. The interplay among intercellular organelles, such as mitochondria, endoplasmic reticulum (ER)/sarcoplasmic reticulum (SR) and the extracellular space has been the subject of much research, as their dysfunctions are linked with many metabolic diseases, like obesity, stroke and migraine. In order to understand the biological and pathological mechanisms behind such activities, this project investigates the dynamics of calcium concentration in vascular smooth muscle cells by constructing a mathematical model using ordinary differential equations (ODEs). It considers the calcium dynamics in four compartments: the mitochondria, the cytosol, the ER and the extracellular space, whose interactions rely on several ion pumps and channels on cell membranes and intracellular organelles. It particularly explores the effects of inositol 1,4,5-trisphosphate (IP3), extracellular potassium and mitochondrial calcium source on cytosolic calcium dynamics and examines the threshold where bifurcation occurs. It turns out from the numerical simulations of the model that the increase of extracellular potassium concentration first leads to oscillations in cytosolic calcium at around 5.1mM and then the depolarization is induced after 24.9 mM; while adding IP3 and mitochondrial calcium source have no influence on cytosolic calcium dynamics at first, then give rise to oscillations, with bifurcation points of 0.245 µM/s and 1.1 nM/s correspondingly.