The Changes of Collagen Synthesis Following the Active Arthus Reaction in the Guinea Pig Skin
Active Arthus reactions were provoked by injecting 100 μg bovine serum albumin (BSA) into the skin of sensitized guinea pigs. Skin biopsy samples were taken 1, 4, 8, 24, 48, 72 and 120 hours after the provocation. Samples were labeled by intradermal injection of 10 μCi [3, 4- 3H]- proline for 1 hour and specific activity of radioactive proline per amount of protein was determined on 1 N NaOH extract of dermis as total protein synthesized. And the synthesized collagenous protein was measured as 3H-hydroxyproline by the method of Juva and Prockop. The results were compared with those obtained by the control injections of 100 μg BSA into the skin of non-sensitized guinea pigs. The synthesized total protein increased at 1, 4 and 8 hours, decreased at 24 hours and increased again at 72 hours. The time course of collagenous protein synthesis was nearly the same as that of total protein synthesis, however the synthesized collagenous protein was higher than the total protein synthesized 1 and 4 hours after the provocation. It was suggested that collagen synthesis increased in an active Arthus reaction up to 4 hours after the provocation.