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GOMPERTZ SLOPE FOR ALL CAUSES
EXCEPT RETICULAR TUMOURS
10;
DAILY DOSE. R/DAY
Figure VIIl.
A plot of life-shortening to daily dose for mice treated with life-time gamma
rays exposure. Life-shortening its measured by the increase of slope of the
Gompertz function in irradiated as compared to control populations. Open circles
refer to BCF1 and closed circles to LAF1 mice. The dashed line corresponds to
the inferred relationship for single exposures with constant effectiveness per
roentgen of 0.003 R~.
2.
12h,
Data from Sacher [81h].
Guinea-pig
One hundred-day old male and female guinea-pig were started on a frac-
tionated course of radiation (o6 gamma rays) for the entire duration of life
[R2].
Together with a number of control animals, groups receiving 1.35 R,
once or four times a week; 2.6 R, 5 times a week; 6.0 R, 4 times a week; 24 R,
once a week; 6 R, 6 times a week; were included for a total of 344 animals.
The relationship of the log mean after-survival time against the weekly ex-
posure in R was approximately linear and the life-shortening coefficient came
to about 0.06 days/R, in close agreement with the data of Lorenz et al. [16].
At 5.4 R/week a paradoxical early decrease of mortality was noted in males for
which no explanation could be given.
Fatty degeneration of the liver, chro-
nic kidney diseases, spleen amyloidosis and various tumours were noted in the
animals in no obvious correlation with 1ife-span-shortening.