Das S, Powers H J
Division of Child Health, University of Sheffield, UK.
Br J Nutr. 1998 Nov;80(5):485-91.
The effects of maternal intake and gestational age on materno-fetal transport of vitamin C were investigated in female Dunkin-Hartley guinea-pigs. Twenty-four time-mated dams were fed on either a moderate-vitamin C (group A) or a high-vitamin C (group B) diet, throughout pregnancy. At days 49, 63 and 66 of gestation, and at term, three animals from each group were killed and fetuses removed by hysterectomy. Plasma, liver, kidney, lungs, heart, placenta and amniotic fluid were collected from dams and fetuses and subsequently analysed for vitamin C. Fetal plasma and amniotic fluid concentrations showed negative associations with gestational age for both dietary groups, independent of an effect of dam (P < 0.001). A similar, though not significant, effect of gestational age was observed on placental vitamin C and group A fetal tissue concentrations. Fetal plasma, placental and amniotic fluid vitamin C concentrations were significantly higher in group B than group A (P < 0.001), suggesting the influence of maternal diet. Although the level of maternal vitamin C intake can influence the circulating concentration in the fetus, there is a decrease associated with increasing gestational age, independent of the maternal diet. The gestational age-dependent change in the fetal accumulation of vitamin C may reflect changes in the rate of placental transfer.
在雌性Dunkin-Hartley豚鼠中研究了母体摄入量和胎龄对维生素C母婴转运的影响。24只经同期交配的母鼠在整个孕期分别喂食中等维生素C（A组）或高维生素C（B组）饮食。在妊娠第49、63和66天以及足月时，每组处死3只动物，通过子宫切除术取出胎儿。从母鼠和胎儿中收集血浆、肝脏、肾脏、肺、心脏、胎盘和羊水，随后分析其中的维生素C。两个饮食组的胎儿血浆和羊水浓度均与胎龄呈负相关，与母鼠的影响无关（P < 0.001）。在胎盘维生素C和A组胎儿组织浓度上观察到胎龄有类似但不显著的影响。B组胎儿血浆、胎盘和羊水维生素C浓度显著高于A组（P < 0.001），表明母体饮食的影响。尽管母体维生素C摄入量水平可影响胎儿的循环浓度，但与胎龄增加相关的是维生素C浓度下降，与母体饮食无关。胎儿维生素C积累中与胎龄相关的变化可能反映了胎盘转运速率的变化。
