Shupe J L, Bagley C V, Karram M H, Callan R J
Department of Animal, Dairy & Veterinary Sciences, Utah State University, Logan 84322-5600.
Vet Hum Toxicol. 1992 Feb;34(1):1-4.
Placental transfer of fluoride was studied in 40 Holstein cows and related to a previous 7 1/2 y study for comparative purposes. Animals were randomly assigned to fluoride dosage groups of control, 0.51, 1.31 or 2.66 sodium fluoride/d (10, 25, 50 or 100 ug/g feed). Each animal received the dose daily via gelatin bolus for 4-14 d prior to parturition. Maternal heparinized blood samples were collected before dosing and after parturition. Placental cotyledon and calf blood samples were collected from each animal immediately after parturition. Maternal and calf plasma and placental cotyledon fluorine concentrations were determined. Increased levels of fluoride given to pregnant cows resulted in significantly increased (p less than 0.05) maternal plasma and placental cotyledon fluorine concentrations. Calf plasma fluorine concentrations at birth did not significantly increase in relation to the fluoride treatment level of dams. The data support the concept that under normal circumstances in cattle there is a partial placental barrier to fluoride that operates to limit fluoride concentrations in the fetal circulation and tissues.
在40头荷斯坦奶牛中研究了氟化物的胎盘转运，并与之前一项为期7年半的研究进行比较。动物被随机分配到对照组、每天0.51、1.31或2.66毫克氟化钠的剂量组（每克饲料10、25、50或100微克）。每头动物在分娩前4至14天通过明胶丸剂每日接受该剂量。在给药前和分娩后采集母体肝素化血样。在每头动物分娩后立即采集胎盘子叶和犊牛血样。测定母体和犊牛血浆以及胎盘子叶中的氟浓度。给怀孕奶牛增加氟化物水平导致母体血浆和胎盘子叶氟浓度显著增加（p小于0.05）。出生时犊牛血浆氟浓度与母畜的氟化物处理水平无关，没有显著增加。数据支持这样的概念，即在牛的正常情况下，存在部分胎盘屏障来限制氟化物在胎儿循环和组织中的浓度。
