Whole-body exposure of adult rats to X rays at sublethal or lethal doses causes a decrease in hydroxyproline levels in urine and skeletal muscle. Similarly, reduction in the excretion of labeled hydroxyproline in urine following intraperitoneal injection of <tex-math>${}^{14}{\rm C}\text{-proline}$</tex-math>, may be attributed to impaired in vivo hydroxylation of proline. Incorporation of administered <tex-math>${}^{14}{\rm C}\text{-proline}$</tex-math> into <tex-math>${}^{14}{\rm C}\text{-hydroxyproline}$</tex-math> and its distribution in different metabolic forms of collagen in skeletal muscle and skin are markedly reduced in X-irradiated rats. These suggest impaired hydroxylation of proline. However, in vitro proline hydroxylase activity in liver is not affected by radiation treatment. Decreased endogenous oxygen consumption, as observed in liver homogenates of X-irradiated rats, may be one of the factors which affect in vivo proline hydroxylation.

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