Wallach S, Verch R L
J Am Coll Nutr. 1984;3(1):69-74. doi: 10.1080/07315724.1984.10720038.
Since trivalent chromium (Cr+3) transport into certain tissues is rapid, the placental transport of injected high specific activity 51Cr+3 was studied in pregnant rats at days 17-20 of gestation. Three days after the intravenous injection of 51Cr+3, body retention of 51Cr was similar in pregnant and nonpregnant rats, but in the pregnant rats placentofetal uptake of 51Cr accounted for 25-30% of the 51Cr retention. The mean 51Cr content per placentofetal unit was 0.89 +/- 0.03% injected dose. Serum and tissue 51Cr contents per milliliter or gram in the pregnant rats were decreased by 50-80% except in uterus, which was unchanged. Tissue/serum 51Cr ratios were increased by 70-300% in the pregnant rats compared to the nonpregnant controls. These results indicate that the placentofetal unit is capable of extracting large amounts of Cr from the mother, and support the suggestion that maternal Cr is depleted during pregnancy. The data also suggest that body tissues may defend their Cr stores against Cr depletion by adaptive cellular Cr transport mechanisms.
由于三价铬（Cr+3）进入某些组织的速度很快，因此在妊娠第17 - 20天的孕鼠中研究了注射高比活度51Cr+3后的胎盘转运情况。静脉注射51Cr+3三天后，孕鼠和未孕鼠体内51Cr的潴留情况相似，但在孕鼠中，胎盘-胎儿对51Cr的摄取占51Cr潴留量的25 - 30%。每个胎盘-胎儿单位的平均51Cr含量为注射剂量的0.89 +/- 0.03%。除子宫未发生变化外，孕鼠每毫升或每克血清和组织中的51Cr含量降低了50 - 80%。与未孕对照相比，孕鼠的组织/血清51Cr比值增加了70 - 300%。这些结果表明，胎盘-胎儿单位能够从母体中提取大量的铬，并支持孕期母体铬会减少的观点。数据还表明，身体组织可能通过适应性细胞铬转运机制来保护其铬储备免受铬耗竭的影响。
