Abstract: Objective: To investigate the role of transient receptor potential melastatin7 (TRPM7) in platelet derived growth factor (PDGF) and 5-hydroxytryptamine (5-HT)-induced rat pulmonary artery smooth muscle cells (PASMCs)  abnormal proliferation. Methods: PASMCAs were cultured with the explant technique. The expression of TRPM7 was evaluated by RT-PCR, western blot and whole-cell patch clamp. The proliferation of PASMCs was evaluated by MTT assay. TRPM7 inhibitor 2-APB was used to investigate the receptor mechanism of TRPM7-like current and the effects of TRPM7 in abnormal proliferation induced by PDGF and 5-HT. Results: RT-PCR and western blot showed that the TRPM7 mRNA and protein were detected in rat PASMCs. Electrophysiological results showed that the TRPM7 currents were detectable and that PDGF can increase the amplitude of TRPM7 inside and outside currents. 100 μmol•L^-1 2-APB inhibited PDGF and 5-HT-induced abnormal proliferation in rat PASMCs. Conclusion: TRPM7 participates in PDGF and 5-HT-induced abnormal proliferation in rat PASMCs and TRPM7 may be a new target for clinical treatment of pulmonary artery hypertension (PHA).

Key words: transient receptor potential melastatin7 (TRPM7), platelet derived growth factor (PDGF), 5-hydroxytryptamine (5-HT), platelet derived growth factor (PASMCs), pulmonary artery hypertension (PAH)