| Abstract: | The metabolism of collagen in male rats by treatment with bleomycin was studied following the injection of 3H]proline and the determination of specific and total activity of 3H]hydroxyproline in skin collagen fractions and urine. In the case of the bleomycin-treated animals, there was found to be an increase in the neutral salt soluble collagen content with no change in insoluble collagen content as compared to the control group. The specific and total radioactivity of 3H]hydroxyproline in soluble and insoluble collagen fractions was also increased. Examination of 3H]hydroxyproline activity in soluble and insoluble collagen showed that the conversion of soluble to insoluble collagen was improved by the bleomycin-treated group. It was found that this was accompanied by a decrease in urinary excretion of total hydroxyproline and 3H]hydroxyproline during the first 12 hr after the administration of 3H]proline. Therefore, the results of the present investigation clearly indicate that the maturation of soluble to insoluble collagen is promoted and accompanied by a decrease in the catabolism of soluble collagen in the bleomycin-treated animals. In addition, administration of bleomycin increased the synthesis of collagen. |
