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

(1)在肺动脉中，Kv 1.2、Kv1.5、Kv2.1和/或Kv3.1可随O2开放。阿尔法亚单位Kv9.3增强了Kv2.1的O2敏感性，并且β亚基也可以调制阿尔法亚单位的选通属性。本研究评估了DA和PA的K通道的mRNA表达和O2敏感性是否不同。Kvβ亚基的mRNA表达在胎儿血管之间没有显著差异。Kv 9.3在导管中的表达减少可能导致Kv 2.1对O2的敏感性降低，从而导致导管对O2的反应不同于在肺动脉中的反应。(2)作为导管的O2感受器，已经涉及对O2敏感的Kv和KATP，这些离子通道可能在早产儿中发育不良。本研究的目的是研究这些离子通道在导管平滑肌细胞中的发育。在早产儿的DA中，除了O2敏感的Kv外，KATP作为O2-的感受器也是重要的，而不受O2抑制的Kv存在于DA中。

(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.