TY - JOUR
T1 - Recovery from radiation damage in mouse lung
T2 - Interpretation in terms of two rates of repair
AU - Van Rongen, E.
AU - Thames, H. D.
AU - Travis, E. L.
PY - 1993
Y1 - 1993
N2 - A reanalysis was performed of the extensive data set obtained with fractionated irradiations of mouse lung reported by Travis et al. (Int. J. Radiat. Biol. 52, 903-919, 1987). The possibility was investigated that the poor fit of these data to the linear-quadratic model might have been the result of the presence of two rates of repair of sublethal damage instead of one. Therefore, the incomplete-repair linear-quadratic model was adapted to incorporate two independent rates of repair and the data were analyzed using this two-component incomplete-repair model. The results which are subjected to certain qualifications with respect to the assessment of the validity of the confidence limits indicated the presence of two significantly different repair rates, corresponding to a fast-repair half-time (t( 1/2 )) of 0.40 h (0.28, 0.53) and a slow t( 1/2 ) of 4.01 h (1.55, 6.57). A weight factor determined simultaneously indicated that the fast component has approximately four times more weight than the slow component. The α/β value calculated for the entire data set using the same model was 3.8 Gy (3.0, 4.6), which is not significantly different from the α/β of 3.6 Gy (2.8, 4.5) calculated for the 8- and 12-h data only, using the complete-repair linear-quadratic model. An experiment specifically designed to test the significance of the fast-repair component was performed in which mouse lungs were irradiated with two equal dose fractions, separated by intervals ranging from 10 min to 6 h. Data obtained from this experiment allowed only one repair rate to be determined, corresponding to a t( 1/2 ) of only 0.4 h. This finding confirms the presence of a very fast repair rate in mouse lung.
AB - A reanalysis was performed of the extensive data set obtained with fractionated irradiations of mouse lung reported by Travis et al. (Int. J. Radiat. Biol. 52, 903-919, 1987). The possibility was investigated that the poor fit of these data to the linear-quadratic model might have been the result of the presence of two rates of repair of sublethal damage instead of one. Therefore, the incomplete-repair linear-quadratic model was adapted to incorporate two independent rates of repair and the data were analyzed using this two-component incomplete-repair model. The results which are subjected to certain qualifications with respect to the assessment of the validity of the confidence limits indicated the presence of two significantly different repair rates, corresponding to a fast-repair half-time (t( 1/2 )) of 0.40 h (0.28, 0.53) and a slow t( 1/2 ) of 4.01 h (1.55, 6.57). A weight factor determined simultaneously indicated that the fast component has approximately four times more weight than the slow component. The α/β value calculated for the entire data set using the same model was 3.8 Gy (3.0, 4.6), which is not significantly different from the α/β of 3.6 Gy (2.8, 4.5) calculated for the 8- and 12-h data only, using the complete-repair linear-quadratic model. An experiment specifically designed to test the significance of the fast-repair component was performed in which mouse lungs were irradiated with two equal dose fractions, separated by intervals ranging from 10 min to 6 h. Data obtained from this experiment allowed only one repair rate to be determined, corresponding to a t( 1/2 ) of only 0.4 h. This finding confirms the presence of a very fast repair rate in mouse lung.
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U2 - 10.2307/3578360
DO - 10.2307/3578360
M3 - Article
C2 - 8438064
AN - SCOPUS:0027532001
SN - 0033-7587
VL - 133
SP - 225
EP - 233
JO - Radiation research
JF - Radiation research
IS - 2
ER -