高林 俊文, 阿部 洋一, 佐藤 信二, 佐藤 章, 鈴木 雅洲

Toshifumi TAKABAYASHI, Yoichi ABE, Shinji SATO, Akira SATO, Masakuni SUZUKI

東北大学医学部産科学婦人科学教室

Department of Obstetrics and Gynecology, Faculty of Medicine, Tohoku University

キーワード : pulsed ultrasound, teratogenicity, mouse embryo, pulse width, peak intensity

C₃H/He mouse embryos in utero were exposed to experimental intense pulsed ultrasound in day 8 of pregnancy. Fetal anomaly was observed in the mice exposed to 58.6 W/cm² peak intensity pulsed ultrasound for 5 min., but not in the group exposed to reduced peak intensity with the same pulse width and repetition rate. In spite of similar mean acoustic intensity, the group exposed to higher peak intensity that was 59.4 W/cm² produced fetal anomaly, but not by lower peak intensity level. No anomaly of fetal mouse was noted after the exposure to ultrasound with smaller pulse width that was 3 μs, and even with the peak intensity of 60 W/cm². It is suggested that the teratogenicity depends on peak intensity as well as pulse width of the ultrasound. Critical acoustic intensity in day 8 of mouse pregnancy is estimated to be 60 W/cm² in SATP and 1.2 W/cm² in SPTA values.