Finite volume simulation of calcium distribution in a cholangiocyte cell

Abstract

Cholangiocytes are the cells of the liver having a major role in the conditioning of bile used in digestion. Other functions of cholangiocytes are in apoptosis and bicarbonate secretion. The Calcium in the intracellular environment of various cells including cholangiocytes regulates a large number of functions. This regulating mechanism in cholangiocytes has been poorly understood to date. In order to analyze the calcium regulation in cholangiocyte cells, a mathematical model for a one-dimensional steady-state case is constructed in this study. This involves a non-linear reaction-diffusion equation with appropriate boundary conditions. The influx from IP$_{3}$ receptor, ryanodine receptor (RYR), and plasma membrane as well as the efflux of calcium from SERCA pump and plasma membrane have been employed in the model. The finite volume method and Newton-Raphson method have been used to solve the problem. Numerical findings have been used to examine the effects of parameters like diffusion coefficient, rate of SERCA pump efflux, buffer, and influx from plasma membrane on calcium concentration in cholangiocyte cells. The information generated from the model can be useful for understanding the mechanism of cholestatic disorders which can be further useful in the diagnosis and treatment of these disorders.