“…This was in contrast with other phospholipids, turnover of which remained relatively constant during the same period. Somewhat different results were described by Dubois & Rampini (1978), who reported that PtdIns turnover is stimulated during GI and S Abbreviations used: Ptdlns, phosphatidylinositol; PtdIns4P, phosphatidylinositol 4-phosphate; Ptdlns(4,5)P2, phosphatidylinositol 4,5bisphosphate; P-PI, polyphosphoinositide; PtdCho, phosphatidylcholine; PtdEtn, phosphatidylethanolamine; PtdSer, phosphatidylserine; PtdOH, phosphatidic acid; InsP, inositol monophosphate; InsP2, inositol bisphosphate; InsP3, inositol trisphosphate; DMEM, Dulbecco's modification of Eagle's medium. * Present address: CIBA-Geigy Pharmaceuticals, Wimblehurst Road, Horsham, West Sussex RH12 4AB, U.K. t Present address: Parke-Davis Research Unit, Addenbrooke's Hospital Site, Hills Road, Cambridge CB2 2QB, U.K. t To whom reprint requests should be addressed.…”