The effects of anabolic steroids on collagen synthesis in rat skeletal muscle and tendon. A preliminary report.

We measured the activities of prolyl 4-hydroxylase and galactosylhydroxylysyl glucosyltransferase (both enzymes of collagen biosynthesis) and the concentration of hydroxyproline in male rat soleus muscle and Achilles tendon during anabolic steroid treatment at 1 and 3 weeks. The rats were treated using a therapeutic dosage or a dosage that was five times the therapeutic level. After 1 week, the activity of prolyl 4-hydroxylase decreased significantly (P less than 0.01) in both treated groups in the soleus muscle, but the activity of galactosylhydroxylsyl glucosyltransferase decreased significantly (P less than 0.05) only in the group given a therapeutic dose. After 3 weeks, the activities were at the control level. In the Achilles tendon, the activity of prolyl 4-hydroxylase and the hydroxyproline concentration decreased significantly (P less than 0.05) in the group given high doses at 3 weeks. Anabolic steroid treatment seems to have at least a transitory effect on collagen biosynthesis in male rat muscle and tendon; in tendon this effect is seen only with high doses.