Phorbol esters stimulate phosphate accumulation synergistically with A23187 in cultured renal tubular cells

The effects of phorbol esters and diacylglycerol on phosphate accumulation in the cultured mouse kidney cells were investigated to assess the possible role of Ca2+-activated, phospholipid dependent protein kinase (protein kinase C) on the renal phosphate handling. 12-O-tetradecanoyl phorbol-13-acetate (TPA) stimulated phosphate accumulation dose-dependently. TPA-induced phosphate accumulation was synergistically enhanced with A23187. 4 alpha-phorbol 12,13-didecanoate did not stimulate the phosphate accumulation, while 4 beta-phorbol 12,13-didecanoate stimulated it. Additionally, 1-oleoyl-2-acetyl-glycerol exhibited a stimulatory effect on phosphate accumulation. These data indicated that protein kinase C is one of possible regulators of phosphate transport at the renal tubules.