Figure 1.

Effect of H₄R ligands on in vitro MDA-MB-231 cell proliferation. Proliferation was evaluated by the clonogenic assay in a human breast adenocarcinoma cell line. Cells were left untreated or were treated with (A) histamine (Ha), (B) clozapine (Clz), (C) JNJ28610244 (J28) (0.01–50 μmol L⁻¹) and/or 10 μmol L⁻¹ JNJ7777120 (J77). (D) Incorporation of BrdU. Cells were left untreated or were treated with 10 μmol L⁻¹ histamine (Ha), clozapine (Clz), JNJ28610244 (J28) for 48 h. Error bars represent the means ± SEM. (**P < 0.01, ***P < 0.001 vs. Control; &P < 0.05 versus 10 μmol L⁻¹ histamine; ^###P < 0.001 versus 10 μmol L⁻¹ H₄R agonist. ANOVA and Newman–Keuls Multiple Comparison Test).