The individual and combined effects of X-irradiation and hyperthermia on early somite mouse embryos in culture.
The effects of 1) X-irradiation and 2) hyperthermia at a temperature of 43 degrees C individually and in combination have been investigated using cultured 8-day mouse embryos. B6C3F1 embryos were exposed to 0.3-2.0 Gy of X-rays, 5-20 min of heating, or 5 min of heating and irradiation at 0.3, 0.6, and 0.9 Gy. Irradiation alone at 0.3 Gy showed no apparent effect on embryonic development, but irradiation at 0.6-2.0 Gy caused a dose-dependent increase in malformed embryos. Heating alone for 5 min produced no malformed embryos, while heating for 10-20 min caused malformations as a function of heating time. Combined treatments produced higher frequencies (22.2-100%) of malformations than those of the sum of the separate treatments (0-41.7%). Malformations observed were primarily microphthalmia, microcephaly, and open neural tubes. The results indicate that in cultured mouse embryos irradiation combined with a "nonteratogenic dose" of hyperthermia directly exerts an additive effect on formation of the malformed embryos. In addition, a single occurrence of left-sided tail was produced by hyperthermia alone, while four occurrences were produced in combination with radiation.
Nakashima
K
K
Department of Oral Radiology, Asahi University School of Dentistry, Gifu, Japan.
Kawamata
A
A
Fujiki
I
I
Fujiki
Y
Y
D000016:Abnormalities, Radiation-Induced; D000818:Animals; D001835:Body Weight / Q000528:radiation effects; D002490:Central Nervous System / Q000528:radiation effects; D046508:Culture Techniques; D004307:Dose-Response Relationship, Radiation; D005314:Embryonic and Fetal Development / Q000528:radiation effects; D005123:Eye / Q000528:radiation effects; D005328:Fetal Viability / Q000528:radiation effects; D006321:Heart / Q000528:radiation effects; D006358:Hot Temperature / Q000009:adverse effects*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D014965:X-Rays / Q000009:adverse effects*