[Study on the roles of voltaged potassium channels in acute hypoxic pulmonary vasoconstriction].
ABSTRACT To investigate the role of voltage-gated potassium channels in the acute hypoxic pulmonary vasoconstriction.
Thirty Wistar rats were divided into two groups, namely the normoxic group and hypoxic group. The single smooth muscle cell was obtained from the pulmonary artery of Wistar rats with acute enzymatic digestion method. The conventional whole-cell patch clamp technique was used to record the resting membrane potential(Em) and the potassium currents of voltage-gated potassium channel (IKv) in rat pulmonary arterial smooth muscle cells(PASMC). Intracellular application of Kv1.2, Kv1.3, Kv1.5, and Kv2.1 antibodiesè1:125éwas conducted through the whole-cell patch clamp system.
Em of PASMC was depolarized in hypoxia compared with that of control cells. The mixture of Kv1.2, Kv1.3, Kv1.5, and Kv2.1 antibodiesè1:125é depolarized Em and inhibited Ikv in PASMC from normoxic rat,whereas the mixture of Kv1.2, Kv1.3, Kv1.5, Kv2.1 antibodiesè1:125éhad no effects on Ikv and Em in hypoxic rats.
Kv1.2, Kv1.3, Kv1.5, Kv2.1 might be oxygen sensitive potassium channels which mediated acute hypoxic pulmonary vasoconstriction.