Collagen Synthesis and Turnover in the Growing Rat Under the Influence of Methyl Prednisolone.

Abstract

Summary At different time intervals, over a 115 day period skin biopsies were performed in growing rats which had received an initial tracer dose of C¹⁴-glycine. Specific activity values for the different fractions of skin collagen isolated (0.15 M NaCl, 0.5 M NaCl, 0.5 M citrate pH = 3.6 and insoluble) were corrected for growth taking into account changes in surface area, skin thickness and pool size of the particular fraction. The 0.15 M and 0.5 M NaCl fractions in the normally growing rats decayed almost exponentially with T½ of 17 and 20 days. The curve for the insoluble collagen did not reflect the presence of a single component but seemed to indicate a progressive insolubilization. A T½ of 28 days was evident during the period of rapid growth whereas a value close to 300 days could be extrapolated towards the end of the experiment. Corticoid treatment (0.11 and 0.36 mg/day) decreased the turnover rate of all fractions, and caused a decrease on the amount of collagen extractable by neutral salt.