The evaluation on the biological safety of diagnostic ultrasound using radiation-induced apoptosis in the external granular layer of mouse cerebellum

마우스 소뇌과립층의 apoptosis를 지표로 한 진단용 초음파의 안전성 검증

  • Oh, Heon (College of Veterinary Medicine, Chonnam National University) ;
  • Lee, Song-eun (College of Veterinary Medicine, Chonnam National University) ;
  • Yang, Jung-ah (College of Veterinary Medicine, Chonnam National University) ;
  • Jo, Sung-kee (Department of Food Irradiation, KAERI) ;
  • Chung, Chi-young (College of Veterinary Medicine, Chonnam National University) ;
  • Son, Chang-ho (College of Veterinary Medicine, Chonnam National University) ;
  • Kim, Sung-ho (College of Veterinary Medicine, Chonnam National University)
  • 오헌 (전남대학교 수의과대학 수의학과) ;
  • 이송은 (전남대학교 수의과대학 수의학과) ;
  • 양정아 (전남대학교 수의과대학 수의학과) ;
  • 조성기 (한국원자력연구소 식품조사팀) ;
  • 정치영 (전남대학교 수의과대학 수의학과) ;
  • 손창호 (전남대학교 수의과대학 수의학과) ;
  • 김성호 (전남대학교 수의과대학 수의학과)
  • Received : 1999.04.16
  • Published : 1999.06.22

Abstract

We have studied, by a nonisotopic in situ end-labeling(ISEL) technique, frequency of apoptosis in the external granular layer(EGL) of the cerebellum of immature mice by ${\gamma}$-rays irradiation from $^{60}Co$ or diagnostic ultrasound exposure. The total number of normal cells and cells showing morphological features of apoptosis were counted. The frequency of apoptotic cells was expressed as a percentage of the total number of cells in EGL. The extent of changes following 200 cGy(1090 cGy/min) was studied at 2, 4, 6, 8, 12, or 24 hours after exposure. The maximal frequency was found 6~8 hours after exposure. The immature mice that received 18, 36, 54, 108, 198, 396 cGy of ${\gamma}$-rays or diagnostic ultrasound(7.5MHz, 4.2mW, $I_{SPTA}=7.9mW/cm^2$, $I_{SPTA}=114.3W/cm^2$) for 10 or 30 minutes were examined 6 hours after irradiation. Measurements performed after ${\gamma}$-ray irradiation showed a dose-related increase in apoptotic cells in each of the mice studied. The dose-response curves were analyzed by a linear-quadratic model ; frequency of apoptotic cell in the EGL was y = $(0.1349{\pm}0.01175)D$+$(-0.0001522{\pm}0.0000334)D^2$+0.048($r^2$ = 0.981, D = dose in cGy). In the experiment of ultrasound exposure, the frequency of apoptotic cell was $0.106{\pm}0.130$(10 minutes exposure) and $0.167{\pm}0.220$(30 minutes exposure). We estimated the relative dose of the yield from the experiment with ultrasound by substituting the yield from ultrasound exposure into the curve from the ${\gamma}$-irradiation. The relative dose of ultrasound exposure compared with ${\gamma}$-irradiation were 0.432 cGy(10 minutes exposure) and 0.885 cGy(30 minutes exposure). We have found that there is no evidence to indicate that diagnostic ultrasound involves a significant risk.

Acknowledgement

Supported by : 전남대학교