RESUMO
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. This cross-link is located subterminally as long as it is not removed by limited pepsin digestion. It was concluded that the physiological decrease in solubility and the decrease in solubility observed in chronically irradiated animals have a different molecular background.
Assuntos
Envelhecimento , Colágeno/efeitos da radiação , Animais , Fenômenos Químicos , Química , Cromatografia , Colágeno/análise , Colágeno/fisiologia , Eletroforese em Gel de Poliacrilamida , Raios gama , Masculino , Doses de Radiação , Ratos , Ratos Endogâmicos , Pele/análiseRESUMO
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.
Assuntos
Neoplasias Pulmonares/urina , Prolina/análogos & derivados , Colágeno/metabolismo , Humanos , Hidroxiprolina/metabolismo , Prolina/urinaRESUMO
It has been evidenced in a single case of bronchogenic carcinoma, that the proportion of collagen type II is increased in the diseased tissue. During the experimental work the collagenous stroma was isolated, subjected to cyanogen bromide cleavage and the relative proportion of individual types of collagen was judged according to the occurence of alpha1(I)CB3 and alpha1 (II)CB3 peptides. The nature of these peptides was proved by the chromatographic behavior during CM-cellulose chromatography, Ultrogel AcA 54 separation and by their amino acid composition.