Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (Unicamp), Campinas, Brazil.
Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (Unicamp), Campinas, Brazil.
Life Sci. 2020 Feb 15;243:117257. doi: 10.1016/j.lfs.2020.117257. Epub 2020 Jan 7.
Electrical field stimulation (EFS) has been used for decades in classical pharmacological preparations in order to characterize the mediators released by neural endings involved in smooth muscle contraction or relaxation. Since most of the human umbilical cord has no innervation, EFS has never been used in this preparation. This study aimed to investigate the effect of EFS on vascular responsiveness from human umbilical cord. Segments of the human umbilical cord were obtained from normotensive parturients and the human umbilical artery (HUA) and the human umbilical vein (HUV) were isolated and mounted in organ bath chambers. Electrical field stimulation-induced contractions in both HUA (2.35 ± 1.31 mN and 3.77 ± 2.31 mN for 8 Hz and 16 Hz respectively, n = 24) and HUV (3.81 ± 2.54 mN and 6.26 ± 4.51 mN for 8 Hz and 16 Hz respectively, n = 25). The addition of tetrodotoxin (1 μM) did not alter the EFS-induced contractions in both tissues (n = 5). Pre-incubation with atropine (10 and 100 μM), glibenclamide (10 μM) and indomethacin (10 μM) did not affect the EFS-induced contractions in both tissues. The contractions of both vessels were significantly reduced by pre-incubation of the tissues with phentolamine (10 and 100 μM). The endothelium removal almost abolished the EFS- induced contractions in both vessels (n = 5). In sandwich preparation, donor tissue (with endothelium) released a factor (s) that promoted contraction of the recipient tissue (endothelium removal) in both HUA and HUV (n = 5, respectively). Our findings indicate a potential role of endothelium-derived catecholamines in modulating HUA and HUV reactivities.
电场刺激 (EFS) 在经典药理学制剂中已使用了数十年，用于表征参与平滑肌收缩或松弛的神经末梢释放的介质。由于大多数人类脐带没有神经支配，因此从未在该制剂中使用 EFS。本研究旨在探讨 EFS 对人脐带血管反应性的影响。从正常分娩的产妇中获得人脐带段，并分离和安装在器官浴槽中。在人脐动脉（HUA）和人脐静脉（HUV）中，EFS 诱导的收缩分别为 2.35±1.31 mN 和 3.77±2.31 mN（分别为 8 Hz 和 16 Hz，n=24）和 3.81±2.54 mN 和 6.26±4.51 mN（分别为 8 Hz 和 16 Hz，n=25）。在两种组织中，加入河豚毒素（1 µM）并没有改变 EFS 诱导的收缩（n=5）。预先孵育阿托品（10 和 100 µM）、格列本脲（10 µM）和吲哚美辛（10 µM）均不能影响两种组织中 EFS 诱导的收缩。预先孵育酚妥拉明（10 和 100 µM）可显著减少两种血管的收缩。内皮去除几乎消除了两种血管中 EFS 诱导的收缩（n=5）。在三明治制剂中，供体组织（具有内皮）释放了一种因子（s），该因子促进了接受组织（内皮去除）的收缩，在 HUA 和 HUV 中均如此（n=5，分别）。我们的发现表明内皮衍生儿茶酚胺在调节 HUA 和 HUV 反应性方面可能发挥作用。
