Figure 6.

Characterization of inositol phosphate formation in the cells expressing human P2Y₂ receptor. CHO (A), Namalwa (B), and Jurkat (C) cells were transfected with pEGFP-N1/hP2Y₂-R cDNA, and the fluorescence histograms for wild-type (gray filling) and hP2Y₂-R-transfected (bold line) cells are shown. (D) Wild-type CHO and CHO-P2Y₂-R cells, labeled overnight with [³H]inositol, were incubated with exogenous nucleotide agonists and lymphocyte suspensions for 5 and 30 min, respectively. Nucleotide concentrations and lymphocyte amounts are indicated as μmol/L and 10⁶ cells/well. (E) Namalwa (Nam) and Jurkat (Jur) cells and their P2Y₂-R transfectants were also radiolabeled with [³H]inositol and incubated without and with 1–10 μM ATP. [³H]inositol phosphates were quantified by ion-exchange chromatography. The data are mean ± SEM (n = 3–5). * p < 0.05 compared with nontreated controls. ** p < 0.05 for P2Y₂-R-transfectants compared with wild-type cells.