抄録
We investigated the characteristics of UTP-induced currents in rat small pulmonary artery smooth muscle cells, using whole cell patch-camp technique. In the condition of high Ca2+ bath solution (100 mM Ca2+) and Cs+ rich pipette solution, 100 μM UTP elicited inward current at holding potential -60 mV. However, UTP failed to evoke the inward current in NMDG-Asp extracellular solution. The induced inward currents were not inhibited by 100 μM niflumic acid. U-73122 (5 μM), a specific PLC inhibitor, attenuated the UTP-induced current but U-73343 (5 μM), an inactive form of U-73122, had no effect. Treatment with 2APB (50 μM) and Xestospongin C (10 μM) inhibited the induced current. These results suggest that UTP elicits inward current independent of Cl− current in high Ca2+ solution. In addition, the current activation mechanisms may involved in PLC activation. [Jpn J Physiol 55 Suppl:S139 (2005)]
