Fractionated irradiation augments inter-strain variation of skin reactions among three strains of mice.
The multifraction regimens commonly used in conventional clinical radiotherapy are largely based on radiobiological experiments. However, no experimental reports on skin reactions focusing on inter-strain differences have displayed clinical relevance to the fractionated dose schedule. In this study, mice of inbred strains A/J, C57BL/6J, and C3H/HeMs were used to reveal inter-strain difference after multifractionated irradiation. Irradiation was performed daily at graded doses of 30-60 Gy total doses, with 10 fractions of 3-6 Gy. Acute skin reactions following irradiation were scored for 50 days after irradiation. Dividing a dose into a number of fractions obviously spared skin damage in the three strains of mice. No mouse exhibited a skin damage score more than 1.5, while single dose irradiation resulted in skin damage scores up to 3. The three different strains, however, showed varying susceptibility to fractionated irradiation within the range under 1.5. C3H/HeMs did not display any skin reaction after irradiation with 40 Gy total dose, while C57BL/6J and A/J demonstrated various skin reactions. Different latent periods of damage were also observed among the strains after irradiation at each dose. Our data suggest that genetic factors cause obvious variations in severity of damage and latent period after fractionated irradiation.
Ohta
Toshie
T
Frontier Research Center, National Institute of Radiological Sciences, Chiba-ken, Japan.
Iwakawa
Mayumi
M
Oohira
Chisa
C
Noda
Shuhei
S
Minfu
Yang
Y
Goto
Miyako
M
Tanaka
Hiroko
H
Harada
Yoshinobu
Y
Imai
Takashi
T
D000818:Animals; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D005260:Female; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D011833:Radiation Injuries, Experimental; D011836:Radiation Tolerance; D011879:Radiotherapy Dosage; D012867:Skin / Q000528:radiation effects*; D013045:Species Specificity; D013997:Time Factors