Are the changes in collagen caused by chronical X-irradiation similar to aging?

It has been shown that in the skin of chronically irradiated rats the proportion of collagen type III as compared to collagen type I is increased; on the other hand, no changes in the overall proportion to collagen were observed in the skin. It appears that the increased proportion of collagen type III in chronically irradiated rats is responsible for the decreased solubility of cutaneous collagen in these animals. Concomitantly, indirect evidence was accumulated for the presence of an additional cross-link in type III collagen, present only when irradiated animals served as the collagen source.

Decrease in pyrrole-2-carboxylic acid excretion during lung cancer disease.

A statistically significant decrease of pyrrole-2-carboxylic acid in urine was observed in lung cancer of stage I (TNM classification) when compared to that of healthy miners (chronically exposed to radiation) from the uranium industry. The difference vanishes in stage II of the disease and reappears in stage III. While nonmalignant lung diseases (bronchopneumonia and chronic bronchitis) do not interfer in the stage I with the drop of pyrrole-2-carboxylic acid excretion, in stage III of lung cancer the decrease is less pronounced and cannot be differentiated from that found in bronchopneumonia or chronic bronchitis.