The effects of x-irradiation on collagen metabolism in rat skin.

Collagen metabolism in rat skin and the response to X-radiation are studied during three consecutive hair-cycles. Collagen biosynthesis and turnover, assessed by the hydroxylation of [U-14C]-proline, proceeds as a function of the periodic hair-growth phenomenon. A single X-radiation treatment to the skin does not affect the amino-acid composition of collagen, but reduces the proline hydroxylation capacity of the fibroblasts. The initial damage to the tissue, resulting in a reduced collagen concentration of the skin, particularly noticeable after several hair-cycles, is at least partially responsible for the delayed skin lesions after irradiation.