| Abstract: | The effects of phorbol esters and diacylglycerol on phosphate uptake in opossum kidney (OK) cells were investigated to assess the possible role of Ca2+-activated, phospholipid dependent protein kinase (protein kinase C) on renal phosphate handling. OK cells are widely used as a model of proximal renal tubular cells and are reported to possess a Na+-dependent phosphate transport system. Phorbol-12,13-dibutyrate (PDBu) inhibited phosphate uptake. This inhibitory effect was synergistically enhanced with A23187. 4 beta-phorbol 12,13-didecanoate inhibited phosphate uptake, while 4 alpha-phorbol 12,13-didecanoate did not. 1-oleoyl-2-acetyl-glycerol (OAG), a synthetic diacylglycerol, also exhibited an inhibitory effect on phosphate uptake. These data suggest the possible involvement of protein kinase C in proximal renal tubular phosphate transport. |
