“…It is well known that in a variety of cell types such as muscular cells (Fleischer et al, 1985;Campbell et al , 1987;Iino et al, 1988), neurons (Lipscombe et al, 1988;Hernandez-Cruz et al, 1990;Zacchetti et al, 1991), endocrine cells (Burgoyne et al, 1989;Malgaroli et al, 1990) and the pancreatic acinar cells (Wakui et al, 1990), caffeine increases the intracellular free calcium ([Ca 2+ ] i ) level through ryanodine, a neutral plant alkaloid, -sensitive or -insensitive Ca 2 + channel located in intracellular calcium stores. However, there is no informations about the action of caffeine and ryanodine on the cellular calcium change in renal epithelial cells.…”