Karpakka · The American journal of sports medicine 1992 · controlled animal experiment · n=?

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

Cited 37 times in the scientific literature.

Level 5 - mechanism / opinion, no new human data

Animal experimental study

PubMed 1636855 · doi:10.1177/036354659202000305 · record verified 2026-08-29

What was done

Male rats were treated with anabolic steroids at either a therapeutic dosage or a five-fold therapeutic dosage for 1 or 3 weeks. Investigators measured markers of collagen biosynthesis in the soleus muscle and Achilles tendon: prolyl 4-hydroxylase activity, galactosylhydroxylysyl glucosyltransferase activity, and hydroxyproline concentration.

What was found

In the soleus muscle after 1 week, prolyl 4-hydroxylase activity decreased significantly (P < 0.01) in both dosage groups, while galactosylhydroxylysyl glucosyltransferase activity decreased significantly (P < 0.05) only in the therapeutic-dose group; both returned to control levels by 3 weeks. In the Achilles tendon at 3 weeks, prolyl 4-hydroxylase activity and hydroxyproline concentration decreased significantly (P < 0.05) only in the high-dose group. The abstract reports P values but no absolute numbers or baseline values.

Why it matters

The study suggests that anabolic steroids transiently impair biochemical markers of collagen biosynthesis in skeletal muscle and can reduce collagen content markers in tendon at supra-therapeutic doses.

Limits

Animal model in male rats with unknown sample size. The specific steroid compound is not named in the abstract, absolute values and error ranges are omitted, and mechanical properties or long-term structural changes were not evaluated.

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