Briones-Garduño Jesús Carlos, Castillo-Henkel Carlos, López-Canales Jorge Skiold, Díaz de León-Ponce Manuel
Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico, D. F.
Gac Med Mex. 2005 Nov-Dec;141(6):489-94.
Absence of innervation is a hallmark of human umbilical vessels. Intervillous space blood flow is regulated by vasoactive substances and calcium dependent contractility, both in normal and pathological conditions such as preeclampsia-eclampsia.
To obtain additional information on the intracellular calcium contractile effects of serotonin in human umbilical arteries.
Umbilical arteries from normal pregnancies were dissected, cut in 5 mm rings and mounted in a temperature-controlled isolated organ chamber, using calcium-free Krebs solution. The contractile effects of serotonin, lantane, verapamil and cyclopiazonic acid were evaluated at different concentrations using a computer coupled biopac polygraph.
No differences in response were observed in the presence and absence of intracellular calcium. The positive contractile effects observed with serotonin were significantly decreased with repeated stimulation. An increase in the basal tone of the vessel was observed after calcium supplementation was added to the solution. This effect was minimized in the presence of verapamil and lantane. The contractile effects of serotonin in the calcium-free solution were not affected by the presence of cyclopiazonic acid.
Serotonin contractile effects in the human umbilical artery depend mainly on intracellular calcium levels which favor the gradual entrance of this ion over time. Calcium influx induced by serotonin is possible through L and Non-L channels apparently insensitive to ciclopiozonic acid.
缺乏神经支配是人类脐血管的一个特征。在正常和病理状态（如子痫前期 - 子痫）下，绒毛间隙血流受血管活性物质和钙依赖性收缩性调节。
获取关于5-羟色胺对人脐动脉细胞内钙收缩效应的更多信息。
从正常妊娠的脐带中分离出脐动脉，切成5毫米的环，置于温度可控的离体器官浴槽中，使用无钙的克雷布斯溶液。使用计算机连接的生物信号采集系统，评估不同浓度的5-羟色胺、钌红、维拉帕米和环匹阿尼酸的收缩效应。
在有或无细胞内钙的情况下，未观察到反应差异。5-羟色胺引起的正向收缩效应在重复刺激后显著降低。向溶液中添加钙补充剂后，观察到血管基础张力增加。在维拉帕米和钌红存在的情况下，这种效应最小化。无钙溶液中5-羟色胺的收缩效应不受环匹阿尼酸存在的影响。
5-羟色胺对人脐动脉的收缩效应主要取决于细胞内钙水平，随着时间的推移，细胞内钙水平有利于该离子的逐渐进入。5-羟色胺诱导的钙内流可能通过对环匹阿尼酸不敏感的L型和非L型通道。
