RESEARCH ON OXYGEN SENSITIVE K CHANNEL IN THE DUCTUS ARTERIOSUS USING MOLECULAR BIOLOGICAL METHODS

(1)在肺动脉中，Kv 1.2、Kv 1.5、Kv 2.1和/或Kv 3.1可以用O2打开。α亚基Kv9.3增强Kv2.1的O2敏感性，β亚基也可以调节α亚基的门控特性。本研究探讨了DA和PA中K通道的mRNA表达和O2敏感性是否存在差异。Kv β亚单位的mRNA表达在胎儿血管中无显著差异。Kv 9.3在肺动脉导管中的表达减少可能会降低Kv 2.1对O2的敏感性，从而导致肺动脉导管对O2的反应不同于肺动脉。(2)作为导管的氧传感器，氧敏感的Kv和KATP已被牵连，这些离子通道可能是欠发达的早产儿。本研究的目的是研究这些离子通道在导管平滑肌细胞的发展。O2敏感性钾通道和KATP在早产胎儿发育不全，除O2敏感性Kv外，KATP在导管中也是重要的O2敏感器，而Kv不受O2的抑制，在早产和成熟胎儿的DA中都存在。

(1) In the pulmonary artery, Kv 1.2, Kv1.5, Kv2.1, and/or KV3.1 may open with O2. An alpha-subunit Kv9.3 enhances the O2-sensitivity of Kv2.1 and beta-subunits may also modulate gating properties of the alpha-subunits. The present study evaluated if the expression of mRNA and O2-sensitivity of the K channels in the DA are different from those in the PA.There was no significant diffrences in the mRNA expression of Kv beta-subunits among the fetal vessels. Decreased expression of Kv 9.3 in the ductus may reduce the O2-sensitivity of Kv 2.1, which in turn may contribute to the response of the ductus to O2 which is diffrent from that in the pulmonary artery.(2) As an O2 sensor of ductus, O2-sensitive Kv and KATP have been implicated and these ion channels may be underdeveloped in premature newborns. The purpose of the present study was to investigate development of these ion channels in the smooth muscle cells of the ductus. O2-sensitive K channels, which closes with O2, and KATP are underdeveloped in the premature futus, in addition to O2-sensitive Kv, KATP is important as an O2-sensor in the ductus, and Kv, which was not inhibited by O2, was present in the DA both in the premature and mature fetus.