Al-Sannan B, Nandakumaran M, Al-Harmi J, Al-Shammari M, Fouda M
a Obstetrics and Gynecology Department, Faculty of Medicine , University of Kuwait , Kuwait , Kuwait.
b Obstetrics and Gynaecology Department , Adan Hospital , Kuwait , Kuwait.
J Matern Fetal Neonatal Med. 2019 Sep;32(18):3000-3006. doi: 10.1080/14767058.2018.1454425. Epub 2018 Apr 5.
Reports relating to maternal-fetal transport kinetics of chromium, an essential trace element in the human pregnancies are scanty. Hence, we thought it interesting to investigate the transport kinetics of this trace element in the human placenta in late gestation . Human placentae were collected immediately after delivery from normal uncomplicated pregnancies. Chromium chloride solution (GFS Chem Inc, Ohio, USA) at 10 times the physiological concentrations and antipyrine (Sigma Chem Co., St. Louis, USA) as internal reference marker was injected as a single bolus (100 µl) into the maternal arterial circulation of perfused placental lobules and perfusate samples were collected from maternal and fetal circulations over a study period of 5 minutes. National culture and Tissue collection medium, diluted with Earle's buffered salt solution was used as the perfusate. Serial perfusate samples were collected from fetal venous perfusate for a period of 30 minutes. Chromium concentration in perfusate samples was determined using atomic absorption spectrophotometry and the concentration of reference marker, antipyrine was measured by spectrophotometry. Transport kinetics and transport parameters of study and reference markers were assessed using well-established parameters. Differential transport rates of chromium and antipyrine in 10 perfusions differed significantly for 10 and 50% efflux fractions (ANOVA test, < .05) while those of 25, 75, and 90% efflux fractions were not significantly different between the study and reference substances. Chromium transport fraction (TF) averaged 54.9% of bolus dose in 10 perfusions while that of antipyrine averaged 89% of bolus dose, representing 61.80% of reference marker TF. The difference observed in TF values of chromium and antipyrine was statistically significant (Student's -test, < .05). Pharmacokinetic parameters such as area under the curve, clearance, absorption rate, elimination rate of chromium compared to reference marker was significantly different (ANOVA test, < .05) between the study and reference substances. Our studies report for the first time maternal-fetal transport kinetics of chromium in human placenta . Considering the restricted transfer of this essential trace element from maternal to fetal circulation despite its small molecular weight, we hypothesize an active transport of chromium across the human placental membrane. Further studies relating to placental transport kinetics of this trace element in various pregnancy-related disease states are in progress.
关于铬在人类孕期母婴转运动力学的报告很少，铬是人类孕期必需的微量元素。因此，我们认为研究这种微量元素在妊娠晚期人胎盘中的转运动力学很有趣。正常无并发症妊娠分娩后立即收集人胎盘。将生理浓度10倍的氯化铬溶液（美国俄亥俄州GFS化学公司）和作为内参标记物的安替比林（美国圣路易斯西格玛化学公司）以单次推注（100微升）的方式注入灌注胎盘小叶的母体动脉循环中，并在5分钟的研究期间从母体和胎儿循环中收集灌注液样本。用Earle's缓冲盐溶液稀释的国家培养和组织收集培养基用作灌注液。从胎儿静脉灌注液中连续收集30分钟的灌注液样本。使用原子吸收分光光度法测定灌注液样本中的铬浓度，用分光光度法测量参比标记物安替比林的浓度。使用成熟的参数评估研究标记物和参比标记物的转运动力学和转运参数。在10次灌注中，铬和安替比林在10%和50%流出分数下的差异转运率有显著差异（方差分析检验，P＜0.05），而在25%、75%和90%流出分数下，研究物质和参比物质之间没有显著差异。在10次灌注中，铬的转运分数（TF）平均为推注剂量的54.9%，而安替比林的平均为推注剂量的89%，占参比标记物TF的61.80%。铬和安替比林TF值的差异具有统计学意义（Student's检验，P＜0.05）。与参比标记物相比，铬的药代动力学参数如曲线下面积、清除率、吸收率、消除率在研究物质和参比物质之间有显著差异（方差分析检验，P＜0.05）。我们的研究首次报道了铬在人胎盘中的母婴转运动力学。考虑到这种必需微量元素尽管分子量小，但从母体循环到胎儿循环的转运受限，我们推测铬在人胎盘膜上存在主动转运。关于这种微量元素在各种妊娠相关疾病状态下的胎盘转运动力学的进一步研究正在进行中。
