Gyasi I, Harper R G, Wapnir R A
Department of Pediatrics, North Shore University Hospital--Cornell University Medical College, Manhasset, New York 11030, USA.
Biochem Mol Med. 1995 Oct;56(1):70-5. doi: 10.1006/bmme.1995.1058.
In this study we investigated whether two low-molecular-weight (LMW) ligands with high affinity for copper (Cu) play a role in the transplacental transport of Cu in the rat. Dams on days 20-21 of gestation were anesthetized and injected via the femoral vein with 5 mg/kg (79 mumol/kg) Cu in 0.5 ml, as either the acetate [Cu(AcO)2], as a 1;10 mixture with L-histidine [Cu(His)10], or as the Cu-(glycyl-glycyl-L-histidine) [G-G-H] complex. Controls received saline. After laparotomy, several fetuses and their placentas were removed at 0, 10, 20, 40, and 60 min after injection, simultaneously with dam blood. Peak Cu concentration in dam plasma occurred at 10 min and was highest following Cu(AcO)2 injection. At 10 and 20 min the placentas from the Cu(AcO)2 and the Cu(G-G-H) groups had higher Cu levels than the controls. By 40 min placentas from all rats injected with Cu had similar Cu concentrations. In the Cu(AcO)2 group there was a positive correlation between dam plasma and placental Cu (r = 0.527, P < 0.05). A sharp downhill gradient was observed between dam and fetus. Fetal plasma Cu levels did not differ among all groups at any time. The data indicate that LMW ligands do not enhance overall maternal-to-fetal Cu transfer, but that an excess of His may inhibit the release of Cu from placenta to fetus.
在本研究中，我们调查了两种对铜（Cu）具有高亲和力的低分子量（LMW）配体是否在大鼠铜的胎盘转运中发挥作用。在妊娠第20 - 21天，将孕鼠麻醉并通过股静脉注射0.5 ml含5 mg/kg（79 μmol/kg）铜的溶液，分别为醋酸铜[Cu(AcO)₂]、与L - 组氨酸按1:10混合的[Cu(His)₁₀]，或铜 - （甘氨酰 - 甘氨酰 - L - 组氨酸）[G - G - H]复合物。对照组注射生理盐水。剖腹术后，在注射后0、10、20、40和60分钟同时采集孕鼠血液，并取出几只胎儿及其胎盘。孕鼠血浆中铜浓度峰值出现在10分钟，醋酸铜注射后最高。在10和20分钟时，醋酸铜组和铜（G - G - H）组的胎盘铜水平高于对照组。到40分钟时，所有注射铜的大鼠胎盘铜浓度相似。在醋酸铜组中，孕鼠血浆和胎盘铜之间呈正相关（r = 0.527，P < 0.05）。观察到孕鼠和胎儿之间有急剧的下降梯度。所有组胎儿血浆铜水平在任何时候都没有差异。数据表明，低分子量配体不会增强母体到胎儿的整体铜转运，但过量的组氨酸可能会抑制铜从胎盘向胎儿的释放。
