Shaw Jordan, deCatanzaro Denys
Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario L8S 4K1, Canada.
Reprod Toxicol. 2009 Jul;28(1):26-31. doi: 10.1016/j.reprotox.2009.03.003. Epub 2009 Mar 20.
Parabens, a class of preservatives routinely added to cosmetics, pharmaceuticals, and foods, have estrogenic properties. Given that intrauterine implantation of fertilized ova in inseminated females can be disrupted by minute levels of exogenous estrogens, we assessed the impact of parabens upon early gestation. In Experiment 1, butylparaben was administered subcutaneously in several doses ranging from 0.05 to 35 mg/animal/day to inseminated CF-1 mice on days 1-4 of pregnancy. Butylparaben exposure did not affect litter size, the number of pups born, postnatal day 3 litter weights, or the number of pups surviving to postnatal day 5. In contrast, administration of 500 ng/animal/day 17beta-estradiol terminated all pregnancies. In Experiment 2, propylparaben was subcutaneously administered to inseminated CF-1 mice on gestational days 1-4. Dams were sacrificed on gestation day 6 and the number of implantation sites was counted. Propylparaben had no impact on the number of implantation sites observed. Since Experiments 1 and 2 did not yield the anticipated results, an uterotrophic assay was conducted in Experiment 3 to re-evaluate the in vivo estrogenicity of parabens. Ovariectomized CF-1 and CD-1 mice were administered butylparaben in doses ranging from 0.735 to 35 mg per animal for three consecutive days. Mice were sacrificed on the fourth day, and uterine mass was recorded. There was no effect of butylparaben on uterine wet or dry mass at any dose in either strain. In contrast, administration of 17beta-estradiol consistently increased uterine mass in both strains. These data indicate that the estrogen-sensitive period of implantation is not vulnerable to paraben exposure, and that the in vivo estrogenicity of parabens may not be as potent as previously reported.
对羟基苯甲酸酯是一类常用于化妆品、药品和食品中的防腐剂，具有雌激素特性。鉴于授精雌性动物子宫内受精卵的着床会受到微量外源性雌激素的干扰，我们评估了对羟基苯甲酸酯对早期妊娠的影响。在实验1中，于妊娠第1至4天，对授精的CF-1小鼠皮下注射不同剂量（0.05至35毫克/动物/天）的丁基对羟基苯甲酸酯。丁基对羟基苯甲酸酯暴露并未影响窝仔数、出生幼崽数、出生后第3天窝仔体重或存活至出生后第5天的幼崽数。相比之下，每天每只动物注射500纳克17β-雌二醇会导致所有妊娠终止。在实验2中，于妊娠第1至4天对授精的CF-1小鼠皮下注射丙基对羟基苯甲酸酯。在妊娠第6天处死母鼠并计算着床部位数量。丙基对羟基苯甲酸酯对观察到的着床部位数量没有影响。由于实验1和2未得出预期结果，在实验3中进行了子宫增重试验以重新评估对羟基苯甲酸酯的体内雌激素活性。对卵巢切除的CF-1和CD-1小鼠连续三天给予每只动物0.735至35毫克的丁基对羟基苯甲酸酯。在第四天处死小鼠并记录子宫重量。在任何剂量下，丁基对羟基苯甲酸酯对两种品系小鼠的子宫湿重或干重均无影响。相比之下，给予17β-雌二醇始终会增加两种品系小鼠的子宫重量。这些数据表明雌激素敏感的着床期不易受到对羟基苯甲酸酯暴露的影响，并且对羟基苯甲酸酯的体内雌激素活性可能不如先前报道的那样强。
