FIGURE 8.

A theoretical model to understand the influence of granule and mitochondria in secretion from cultured and native chromaffin cells. (A) Schematic representation of the 3-D simulation. (B) Upper figure: current to voltage relationships considered in the channel gating kinetic schemes for P/Q- and L-type calcium channels. Lower figure: depolarizing pulse considered in the simulations. (C) Comparison of secretory responses predicted by the model in the absence of mitochondria: theoretical accumulated secretory responses (percentage) for isolated cells and cells in adrenal tissue obtained using the experimental granule distributions. No mitochondria are considered in the medium. (D) Comparison of secretory responses predicted by the model in the presence of mitochondria: theoretical accumulated secretory responses (percentage) for isolated cells and cells in adrenal tissue obtained using the experimental granule and mitochondria distributions.