EVIDENCE FOR A SINGLE POOL OF MYOINOSITOL IN HORMONE-RESPONSIVE WRK-1CELLS

Previous reports have suggested the existence of at least two pools of cellular myo-inositol (Ins); it has been further hypothesized that on ly one of these pools is utilized during hormone-activated, cyclic pho sphatidylinositol (Ptdlns) resynthesis. In an effort to investigate th is possibility, we have undertaken kinetic studies of Ins metabolism i n WRK-1 cells. Our results indicate that a single pool of Ins is invol ved in both basal and activated Ptdlns synthesis. Ins generated by the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PtdlnsP(2)) mixe s with the existing pool of free Ins and is not used exclusively for r esynthesis of Ptdlns. (C) 1995 Wiley-Liss, Inc.