Ikeda G J, Miller E, Sapienza P P, Michel T C, Sager A O
Food Chem Toxicol. 1985 Jun;23(6):609-14. doi: 10.1016/0278-6915(85)90187-5.
[N-Me-14C]Betaine was administered iv as a single dose (5 mg/kg) to pregnant beagle dogs and miniature pigs late in gestation. Two hr after administration of the radiolabel, when the compound was in equilibrium, the dams were killed and the foetuses were removed for determination of the radioactivity in maternal and foetal tissues. Eight litters of dogs (56 foetuses) and four litters of pigs (30 foetuses) were examined. The distribution of betaine in both species showed distinct differences between maternal and foetal tissues, indicating definite placental barriers; the placental distribution factor was estimated to be 52.3% in dogs and 97.8% in pigs. The blood/brain distribution factor was 84.6% in maternal dogs, 89% in maternal pigs, 65.7% in foetal dogs and 0% in foetal pigs. In the dog, maternal liver was the largest depot of the administered betaine, followed by foetal liver. Foetal heart, lung and kidney tissues also incorporated radiolabelled betaine. The highest concentrations of betaine in the pig were found in maternal kidney and liver.
在妊娠后期，给怀孕的比格犬和小型猪静脉注射单剂量（5毫克/千克）的[甲基-¹⁴C]甜菜碱。给予放射性标记物两小时后，当化合物达到平衡时，处死母犬和母猪，并取出胎儿以测定母体和胎儿组织中的放射性。检查了八窝犬（56只胎儿）和四窝猪（30只胎儿）。甜菜碱在两种动物中的分布显示母体和胎儿组织之间存在明显差异，表明存在明确的胎盘屏障；犬的胎盘分布系数估计为52.3%，猪为97.8%。母体犬的血脑分布系数为84.6%，母体猪为89%，胎儿犬为65.7%，胎儿猪为0%。在犬中，母体肝脏是注入甜菜碱的最大储存部位，其次是胎儿肝脏。胎儿心脏、肺和肾脏组织也摄取了放射性标记的甜菜碱。猪体内甜菜碱浓度最高的部位是母体肾脏和肝脏。
