# Combined Effects of Ionizing Radiation and Ultrasound on Malformation in ICR Mice at Organogenesis stage

• Gu, Yeun-Hwa (Department of Radiological Technology, Suzuka University of Medical Science) ;
• Hasegawa, Takeo (Department of Radiological Technology, Suzuka University of Medical Science) ;
• Mori, Takehiko (Department of Radiological Technology, Suzuka University of Medical Science) ;
• Yamamoto, Youichi (Department of Radiological Technology, Suzuka University of Medical Science) ;
• Kusama, Tomoko (Department of Health Science, Oita University of Nursing and Health Sciences)
• Published : 1999.03.30

#### Abstract

Pregnant ICR mice were treated with 137Cs gamma-ray / ultrasound on day 8 of gestation. In combined treatments, pregnant mice were treated with both 1.5 Gy of radiation and $1.0W/cm^2$ ultrasound at time intervals of -1, 0, 1, 3 and 6 hours. The mortalities and external malformations were investigated on day 18 of gestation. The threshold dose of mortality induced by radiation on day 8 of gestation was between 0.5 and 1.0 Gy, and that which was induced by ultrasound was between 1.0 and $1.5W/cm^2$. The mortalities in the late-stage of gestation induced by combined treatment with radiation and ultrasound increased synergistically. The threshold dose of exencephaly and anophthalmia induced by radiation were between 0.5 and 1.0 Gy and between 1.0 and 1.5 Gy, respectively. Those of exencephaly and anophthalmia induced by ultrasound were between 1.0 and $1.5W/cm^2$ and more than $1.5W/cm^2$, respectively. In combined treatments, the incidence of exencephaly and anophthalmia were found to increase synergistically. In the mice treated with both agents at a time interval of one hour, the incidence of exencephaly and anophthalmia reached maximum levels.