Fig. 7
Time-dependent activation of the glycosyl-phosphatidylinositol-phospholipase C (GPI-PLC) by Amaryl and insulin in rat adipocytes. Isolated rat adipocytes were photoaffinity-labeled with N3-[32P]cAMP (72,73) and then incubated with increasing concentrations of different sulfonylureas or human insulin for the periods indicated at 30°C. Plasma membranes were prepared by differential centrifugation and then subjected to partitioning between an aqueous and a TX-114 phase. Both phases were measured for radioactivity by liquid scintillation counting. The radioactivity contained in the TX-114 phase due to the presence of the uncleaved amphiphilic version of the GPI protein, Gce1, at time point 0 in the absence of agent was set at 100%. Each point represents the mean ± standard deviation (SD) of (at least) four independent experiments.