FIGURE 2.

CPM expression increases B1R-dependent PI turnover at low agonist concentration. A and B, HEK cells stably expressing B1Rs were transfected for 24 h with increasing concentrations of CPM cDNA or empty vector (pcDNA3), and the expression (A) and activity (B) of CPM were measured. Cells transfected as in A and B were used to determine the effect of CPM on B1R binding of 100 nm DAKD (C) or B1R-dependent PI turnover in response to 10 nm DAKD (D) or 500 nm DAKD (E). The solid bar denotes basal PI turnover without DAKD stimulation. In C, DALKD = binding in the presence of 1 μm des-Arg¹⁰-Leu⁹-kallidin (B1R antagonist). The data in A, D, and E are representative examples from three experiments, and in B and C are expressed as the mean ± S.E. (n = 3).