实时三维超声对中孕期大鼠子代生长发育及神经行为发育的影响

Effect of real-time three-dimensional ultrasound on growth and neurobehavioral development of rat offspring in mid-gestation

目的研究对中孕期大鼠给予不同时间的实时三维超声辐照,观察其对子代神经发育的影响,为实时三维超声的安全应用提供依据。方法妊娠SD雌性大鼠20只,孕14 d,体质量350-380 g。随机分为辐照0 min组（对照组）、辐照10 min组、辐照20 min组、辐照30 min组4组,每组各5只。分别给予0、10、20、30 min超声辐照[探头频率1.5-5.5 MHz,机械指数（MI）=0.8,骨热指数（TIB）=0.8]。观察大鼠子代生长发育及神经行为发育情况。结果辐照30 min组张耳、开眼、门齿萌出时间较对照组延迟（P〈0.05）,而辐照10 min组及辐照20 min组与对照组相比,差异无统计学意义（P〉0.05）。辐照20 min组及辐照30 min组平面翻正、听觉惊愕、空中翻正、断崖回避的达标时间均较对照组延迟（P〈0.05）。开场实验中,辐照30 min组中央区域驻留时间较对照组显著减少（P〈0.05）。结论中孕期实时三维超声辐照20 min以上会导致大鼠子代生长发育及神经行为发育的迟缓。

Objective To investigate the effect of real-time three-dimensional ultrasound irradiation during different exposure time in mid-gestation for neural development of neonatal rats, and provide the basis for security applications of real-time three-dimensional ultrasound. Methods Twenty female SD rats of pregnant 14 days with body weight 350- 380 g were enrolled, which were randomly divided into 4 groups by exposure time： 0-minute group（control group）, 10-minute group, 20-minute group and 30-minute group. The rats received continuous real-time three ultrasound irradiation [1.5- 5.5 MHz, mechanical index（MI） = 0.8 and thermal index bone（TIB） = 0.8]. Then the growth and neurobehavioral development of neonatal rat were observed. Results In 30-minute group, the days of opened ears and eyes, tooth eruption were later than those of control group（P〈0.05）, but there were no significant difference between 10-minute group, 20-minute group and control group（P〈0.05）.The standard days of rat turned over on plane, heard astonished, turned over in air appeared and cliff parry after birth in 20-minute group and 30-minute group were later than those in control group（P〈0.05）. Open field test indicated that movement duration in central area of 30-minute group was less than that of control group（P〈0.05）. Conclusion It is demonstrated that real-time three-dimensional ultrasound exposure during pregnancy over 20-minute could effect the development of physical and nervous behavior retardation in rat offspring.