Oxygen Sensation,Signal Transduction And Potassium Ion Channels In Hypoxic Pulmonary Hypertension

The properties of the potassium channels of pulmonary artery smooth muscle cells isolated from rats were studied with patch-clamp technique in the conventional whole-cell configuration. The results indicated that voltage-gated potassium currents and calcium-activated K+ currents can be recorded under given conditions. Calcium-activated K+ currents can be inhibited by 5mmol/L TEA, voltage-gated potassium currents, which can be inhibited by 5mmol/L 4-AP, contained at least three components: a rapidly inactivating potassium current (Ka), a slowly inactivating potassium current (Kst) and delayed rectifier potassium current (Kdr). In different cells these three components constituted voltage-gated potassium current in different proportion, Activation curve of voltage-gated potassium currents can be got through tail currents, and From instantaneous currents potassium equilibrium potential can be deduced , it is about -72mv.