Arachidonic acid inhibits phosphate transport by cultured renal cells

Because arachidonic acid and its metabolites are reported to be intracellular messengers of various exogenous stimuli, we studied whether arachidonic acid influences phosphate transport by cultured mouse renal epithelial cells. Arachidonic acid, at 10(-7)-10(-4)M, inhibited phosphate transport without influencing cyclic adenosine 3':5'-monophosphate production. Nordihydroguaiaretic acid and indomethacin, inhibitors of arachidonic acid metabolism, did not cancel the arachidonic acid-induced inhibition of phosphate transport. Furthermore, unsaturated fatty acids other than arachidonic acid also inhibited phosphate transport and their inhibitory effect increased as the number of double bond increased. These data demonstrate that arachidonic acid inhibits the phosphate transport by the cultured renal epithelial cells, probably not via conversion to its metabolites.