Vorhees C V, Acuff-Smith K D, Weisenburger W P, Meyer R A, Smith N B, O'Brien W D
Division of Basic Science Research, Children's Hospital Research Foundation, Cincinnati, Ohio 45229-2899.
Teratology. 1991 Dec;44(6):667-74. doi: 10.1002/tera.1420440609.
Pregnant Sprague-Dawley rats were trained to remain immobile when placed in water in an ultrasound exposure tank and exposed to 0, 0.1, 2.0, or 30.0 W/cm2 ISPTA (spatial peak, temporal average), 3.0-MHz continuous wave (cw) ultrasound on embryonic (E) days 4-19 for approximately 15 min/day. On E20 fetuses were removed; weighed; examined for external, skeletal, and visceral malformations; and uteri were examined for resorptions. Analyses revealed no increase in pre-implantation loss and no effects on maternal body weight, food, or water consumption. No increase in skeletal or visceral malformations was found, in fact exposed groups had a lower incidence of defects than controls. A significant increase in resorptions in the lowest exposure group (0.1 W/cm2) was obtained, but the effect was isolated, non-dose dependent and not credible as a treatment-related effect. No reduction in fetal weight was obtained, in fact the lowest (0.1-W/cm2) and middle (2.0-W/cm2) exposure level groups weighed slightly more than controls. The immobility procedure succeeded in avoiding anesthetization or forced restraint of the dams, thereby eliminating these factors as potential confounders. The results demonstrated that in unanesthetized, unrestrained rats in utero exposure to incident intensities of ultrasound of up to 30.0 W/cm2 cw ultrasound (or estimated internal exposures of 4-21 W/cm2, depending on body orientation to the incident beam) produced no evidence of embryotoxicity based on fetal necropsy data.
将怀孕的斯普拉格-道利大鼠放入超声暴露箱的水中训练，使其保持不动，然后在胚胎（E）第4至19天，每天暴露于0、0.1、2.0或30.0 W/cm² ISPTA（空间峰值，时间平均值）、3.0 MHz连续波（cw）超声下约15分钟。在E20时取出胎儿；称重；检查外部、骨骼和内脏畸形；并检查子宫是否有吸收情况。分析显示植入前损失没有增加，对母体体重、食物或水的消耗也没有影响。未发现骨骼或内脏畸形增加，实际上暴露组的缺陷发生率低于对照组。最低暴露组（0.1 W/cm²）的吸收情况有显著增加，但这种影响是孤立的，不依赖剂量，且作为与治疗相关的影响不可信。未发现胎儿体重减轻，实际上最低（0.1-W/cm²）和中等（2.0-W/cm²）暴露水平组的体重略高于对照组。不动程序成功避免了对母鼠的麻醉或强制约束，从而消除了这些作为潜在混杂因素的因素。结果表明，在未麻醉、未受约束的大鼠中，子宫内暴露于高达30.0 W/cm² cw超声的入射强度（或根据身体与入射束的方向估计的内部暴露为4-21 W/cm²），根据胎儿尸检数据，没有产生胚胎毒性的证据。
