Perfusion system for studying peptide secretion from endocrine cells with high time resolution

To study the secretion from endocrine cells in culture, we have developed a cell column perfusion system with a time resolution of 4 s. The core of the system is a perfusion chamber with a cell-supporting matrix of monosized polystyrene beads. The particles are solid and can withstand a high pressure gradient without deformation. The minimum amount of cell material required to obtain detectable levels of secretory products is a function of the assay sensitivity, perfusion flow, fraction volume and time resolution. The volume of the perfusion chamber is therefore adjustable to satisfy varying demands of minimum cell number. The general flow characteristics of the system were characterized using radiolabeled substances of various molecular sizes. Using the system in secretory studies of rat pituitary tumor (GH4C1) cells, we have identified differences in secretion profiles that may be related to the kinetics of the different transmembrane and intracellular mechanisms involved.