Jensh R P, Lewin P A, Poczobutt M T, Goldberg B B, Oler J, Goldman M, Brent R L
Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Proc Soc Exp Biol Med. 1995 Nov;210(2):171-9. doi: 10.3181/00379727-210-43937.
An ultrasound exposure tank was specifically designed for experimental bioeffects studies. Thirty-six pregnant rats were anesthetized, immersed to the axilla in a water tank, and exposed on Day 15, 17, and 19 of gestation. Twelve rats were exposed to 5.0 MHz pulsed ultrasound of effective pulse duration equal to approximately 0.170 microseconds, pulse repetition rate (PRF) 1 kHz, and a spatial peak, temporal peak intensity (lsptp) of 500 W/cm2, representing a clinically appropriate exposure level. The spatial peak pulse average (lsppa), spatial peak temporal average (lspta), and instantaneous maximum (lm) intensities were determined to be 100 W/cm2, 24 mW/cm2, and 230 W/cm2, respectively. The maximum rarefraction pressure, pr, was measured as 12.5 x 10(5) Pa, and the total power was 2.5 mW. Twelve other rats were exposed to 1500 W/cm2, lsptp, and 12 were sham insonified. Since the focal area was about 0.05 cm2, computer controlled stepper motors moved the rats through the ultrasound field to ensure uniform exposure of the abdominal/pelvic region. Total exposure time was 35 min. A miniature thermocouple was implanted in a few rats to verify that no significant temperature increase took place due to exposure. A total of 278 offspring were maintained until postnatal Day 60 when they were subjected to two of four behavioral tests in random order within sexes. The results indicate no consistently observed dose-related alterations in adult behavior due to prenatal fetal exposure to 5.0 MHz ultrasound below an intensity (lsptp) of 1500 W/cm2.
专门设计了一个超声暴露槽用于实验性生物效应研究。36只怀孕大鼠被麻醉后，将其腋窝以下部位浸入水槽中，并在妊娠第15、17和19天进行暴露。12只大鼠暴露于频率为5.0 MHz、有效脉冲持续时间约为0.170微秒、脉冲重复频率（PRF）为1 kHz且空间峰值、时间峰值强度（Isptp）为500 W/cm²的脉冲超声下，这代表了临床适用的暴露水平。测定空间峰值脉冲平均（Isppa）、空间峰值时间平均（Ispta）和瞬时最大值（Im）强度分别为100 W/cm²、24 mW/cm²和230 W/cm²。最大负压pr测量值为12.5×10⁵ Pa，总功率为2.5 mW。另外12只大鼠暴露于Isptp为1500 W/cm²的超声下，12只大鼠进行假照射。由于聚焦区域约为0.05 cm²，计算机控制的步进电机将大鼠移动通过超声场，以确保腹部/盆腔区域均匀暴露。总暴露时间为35分钟。在几只大鼠体内植入了微型热电偶，以验证暴露不会导致明显的温度升高。总共278只后代饲养至出生后第60天，然后按性别随机顺序接受四项行为测试中的两项。结果表明，产前胎儿暴露于强度（Isptp）低于1500 W/cm²的5.0 MHz超声下，未观察到与剂量相关的、持续一致的成年行为改变。
