Mohammed Riazudin, Cavallaro Giacomo, Kessels Carolina G A, Villamor Eduardo
Department of Pediatrics, Maastricht University Medical Center (MUMC+), Research Institute Growth and Development (GROW) and Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, P. Debyelaan 25, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands.
Neonatal Intensive Care Unit, Department of Clinical Sciences and Community Health, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy.
J Comp Physiol B. 2015 Oct;185(7):783-96. doi: 10.1007/s00360-015-0917-5. Epub 2015 Jun 29.
The chicken extraembryonic arterial system comprises the allantoic arteries, which irrigate the gas exchange organ (the chorioallantoic membrane, CAM) and the yolk sac (YS) artery, which irrigates the nutritional organ (the YS membrane). We compared, using wire myography, the reactivity of allantoic and YS arteries from 19-day chicken embryos (total incubation 21 days). The contractions induced by KCl, the adrenergic agonists norepinephrine (NE, nonselective), phenylephrine (α1), and oxymetazoline (α2), electric field stimulation (EFS), serotonin, U46619 (TP receptor agonist), and endothelin (ET)-1 and the relaxations induced by acetylcholine (ACh), sodium nitroprusside (SNP, NO donor), forskolin (adenylate cyclase activator), and isoproterenol (β-adrenergic agonist) were investigated. Extraembryonic allantoic arteries did not show α-adrenergic-mediated contraction (either elicited by exogenous agonists or EFS) or ACh-induced (endothelium-dependent) relaxation, whereas these responses were present in YS arteries. Interestingly, the intraembryonic segment of the allantoic artery showed EFS- and α-adrenergic-induced contraction and ACh-mediated relaxation. Moreover, glyoxylic acid staining showed the presence of catecholamine-containing nerves in the YS and the intraembryonic allantoic artery, but not in the extraembryonic allantoic artery. Isoproterenol- and forskolin-induced relaxation and ET-1-induced contraction were higher in YS than in allantoic arteries, whereas serotonin- and U46619-induced contraction and SNP-induced relaxation did not significantly differ between the two arteries. In conclusion, our study demonstrates a different pattern of reactivity in the arteries perfusing the gas exchange and the nutritional membranes of the chicken embryo.
鸡胚外动脉系统包括尿囊动脉，其为气体交换器官（绒毛尿囊膜，CAM）供血，以及卵黄囊（YS）动脉，其为营养器官（YS膜）供血。我们使用线肌描记法比较了19日龄鸡胚（总孵化期21天）的尿囊动脉和YS动脉的反应性。研究了氯化钾、肾上腺素能激动剂去甲肾上腺素（NE，非选择性）、去氧肾上腺素（α1）和羟甲唑啉（α2）、电场刺激（EFS）、5-羟色胺、U46619（TP受体激动剂）和内皮素（ET）-1诱导的收缩，以及乙酰胆碱（ACh）、硝普钠（SNP，一氧化氮供体）、福斯可林（腺苷酸环化酶激活剂）和异丙肾上腺素（β-肾上腺素能激动剂）诱导的舒张。胚外尿囊动脉未表现出α-肾上腺素能介导的收缩（由外源性激动剂或EFS引起）或ACh诱导的（内皮依赖性）舒张，而这些反应在YS动脉中存在。有趣的是，尿囊动脉的胚内段表现出EFS和α-肾上腺素能诱导的收缩以及ACh介导的舒张。此外，乙醛酸染色显示在YS和胚内尿囊动脉中存在含儿茶酚胺的神经，但在胚外尿囊动脉中不存在。异丙肾上腺素和福斯可林诱导的舒张以及ET-1诱导的收缩在YS动脉中比在尿囊动脉中更高，而5-羟色胺和U46619诱导的收缩以及SNP诱导的舒张在两条动脉之间没有显著差异。总之，我们的研究表明，在为鸡胚的气体交换膜和营养膜供血的动脉中，反应性模式不同。
