Stochastic effects in intercellular calcium spiking in hepatocytes

We carry out a Monte Carlo simulation of stochastic effects for two models of intercellular calcium wave propagation in rat hepatocytes. Both models i nvolve gap junction diffusion by a second messenger. We find that, in gener al, the stochastic effects improve agreement with experiment, for a reasona ble choice of model parameters. Both stochastic models exhibit baseline flu ctuations and variations in the peak heights of Ca2+. In addition, we find for one model that there is a distribution of latency times, rather than a single latency time, with a distribution width which is comparable to the e xperimental observation of spike widths. We also find for the other model w ith low gap junction diffusion that it is possible for cell multiplets to o scillate independently initially, but to subsequently become synchronized. (C) 2001 Academic Press.