Ludwig Boltzmann Institute for Lung Vascular Research, Neue Stiftingtalstraße 6, 8010 Graz, Austria.
Experimental Anaesthesiology, Department of Anaesthesiology and Intensive Care Medicine, Medical University of Graz, Auenbruggerplatz 5, 8036 Graz, Austria.
Int J Mol Sci. 2022 Apr 23;23(9):4681. doi: 10.3390/ijms23094681.
The transition from the fetal to the neonatal circulation includes dilatation of the pulmonary arteries (PA) and closure of the Ductus Arteriosus Botalli (DAB). The resting membrane potential and various potassium channel activities in smooth muscle cells (SMC) from fetal and neonatal PA and DAB obtained from the same species has not been systematically analyzed. The key issue addressed in this paper is how the resting membrane potential and the whole-cell potassium current (IK) change when PASMC or DABSMC are transitioned from hypoxia, reflecting the fetal state, to normoxia, reflecting the post-partal state. Patch-clamp measurements were employed to characterize whole-cell K channel activity in fetal and post-partal (newborn) PASMC and DABSMC. The main finding of this paper is that the SMC from both tissues use a similar set of K channels (voltage-dependent (Kv), calcium-sensitive (KCa), TASK-1 and probably also TASK-2 channels); however, their activity level depends on the cell type and the oxygen level. Furthermore, we provide the first evidence for pH-sensitive non-inactivating K current in newborn DABSMC and PASMC, suggesting physiologically relevant TASK-1 and TASK-2 channel activity, the latter particularly in the Ductus Arteriosus Botalli.
从胎儿循环向新生儿循环的转变包括肺动脉 (PA) 的扩张和 Botalli 动脉导管 (DAB) 的关闭。来自同一物种的胎儿和新生儿 PA 和 DAB 的平滑肌细胞 (SMC) 的静息膜电位和各种钾通道活性尚未得到系统分析。本文解决的关键问题是，当 PASMC 或 DABSMC 从反映胎儿状态的缺氧转变为反映产后状态的正常氧时，静息膜电位和全细胞钾电流 (IK) 如何变化。膜片钳测量用于表征胎儿和产后 (新生儿) PASMC 和 DABSMC 的全细胞 K 通道活性。本文的主要发现是，来自两种组织的 SMC 使用类似的一组 K 通道（电压依赖性 (Kv)、钙敏感性 (KCa)、TASK-1 通道，可能还有 TASK-2 通道）；然而，它们的活性水平取决于细胞类型和氧气水平。此外，我们提供了新生儿 DABSMC 和 PASMC 中 pH 敏感非失活 K 电流的第一个证据，表明存在与生理相关的 TASK-1 和 TASK-2 通道活性，后者在 Botalli 动脉导管中尤为明显。
