Fig. 5.
Kinetics of [3H]-lyso-PI uptake. Transfer of [3H]-lyso-PI from donor vesicles to the cell membrane of lymphocytes was measured by scintillation counting of the incubation medium from EGTA-containing samples. The 100% value was obtained by measuring an aliquot of solution of 11.25 μmol/L [3H]-lyso-PI (concentration of substrate added to the cells). The kinetics of spontaneous uptake of the lipid by the cells shows that its concentrations in the medium plateaued at about 25% within 5 minutes. Beyond this time, the rate of lyso-PI transfer was evidently reduced. Data are the mean ± SD of at least 3 separate experiments.