FIGURE 5.

Recovery rate of histamine-induced calcium mobilization upon dissociation of antihistamines from the H₁R. (A) HeLa cells were pre-incubated overnight with 10x K_i concentrations of the respective antihistamine. The next day antihistamine dissociation was induced by two rapid wash steps followed by injection of histamine at the indicated time points and calcium mobilization was measured. The resulting calcium-dependent fluorescent-traces (B) were quantified by the peak fluorescence. (C) Peak fluorescence was plotted against the time between antagonist removal and histamine injection. Representative graphs are shown of ≥3 experiments, with single measurements per time point. The histamine-induced peak fluorescence was normalized to the average peak fluorescence of buffer pre-treated cells.