The effect of x-irradiation at weaning stage on the activity of hexobarbital hydroxylation in male rate liver was studied during development. The increase of activity at the postweaning period was suppressed partially by 200 R irradiation and completely by 400 R, without remarkable change in the microsomal protein content of liver. Activities of microsomal electron transport system were inhibited only slightly at 40 days of age in 400 R irradiated rats, but both content of cytochrome P-450 and spectral change induced by hexobarbital were suppressed considerably. The activity of hexobarbital hydroxylation relative to the magnitude of cytochrome P-450 spectral change was about 60% lower than that of control. Adenosine triphosphatase and inosine diphosphatase activities were rather higher than those of control, while glucose 6-phosphatase activity was lower than that of control at 40 days of age in irradiated rats. Results are discussed in relation to the mechanism of effects of x-irradiation on the differentiation of drug metabolizing activity.

This content is only available as a PDF.
You do not currently have access to this content.