title: Androgenic-anabolic steroids associated with mechanical loading inhibit matrix metallopeptidase activity and affect the remodeling of the achilles tendon in rats.
abstract: BACKGROUND
  The indiscriminate use of anabolic-androgenic steroids has been shown to induce pathologic changes in the Achilles tendon in several situations.
  
  
  OBJECTIVE
  To study tendon remodeling in rats treated with anabolic-androgenic steroids combined with an exercise program.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Wistar rats were grouped as follows: sedentary (group I), injected with anabolic-androgenic steroids only (group II), trained only (group III), and trained and injected with anabolic-androgenic steroids (group IV). The trained groups performed jumps in water: 4 series of 10 jumps each, with an overload of 50% to 70% of the animal's body weight and a 30-second rest interval between series, for 6 weeks. Anabolic-androgenic steroids (5 mg/kg) were injected subcutaneously. Activity of matrix metallopeptidases, a marker for tendon remodeling, was analyzed in tissue extracts by zymography on gelatin-sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
  
  
  RESULTS
  Morphological analyses of tendons showed that in group II, the most external layer that covers the tendon was thicker with aggregation of the collagen fibers, suggesting an increase in collagen synthesis. In group IV, an inflammatory infiltrate and fibrosis in tendons as well as a pronounced increase of the serum corticosterone level were observed. This training protocol upregulated matrix metallopeptidase activity, whereas anabolic-androgenic steroid treatment strongly inhibited this activity. The appearance of lytic bands with molecular masses of approximately 62 and 58 kDa suggests the activation of matrix metallopeptidase-2.
  
  
  CONCLUSIONS
  Anabolic-androgenic steroid treatment can impair tissue remodeling in the tendons of animals undergoing physical exercise by down-regulating matrix metallopeptidase activity, thus increasing the potential for tendon injury.
  
  
  CONCLUSIONS
  Since the AAS abuse is so widespread, a better comprehension of the pathological effects induced by these drugs may be helpful for the development of new forms of therapy of AAS-induced lesions.
authors.affiliation: Departamento de Ciências Fisiológicas, Universidade Federal de São Carlos, Rodovia Washington Luis, Km 235, São Carlos, SP, 13565-905, Brazil.
authors.forename: Rita C
authors.initials: RC
authors.lastname: Marqueti
authors.forename: Nivaldo A
authors.initials: NA
authors.lastname: Parizotto
authors.forename: Rosangela S
authors.initials: RS
authors.lastname: Chriguer
authors.forename: Sergio E A
authors.initials: SE
authors.lastname: Perez
authors.forename: Heloisa S
authors.initials: HS
authors.lastname: Selistre-de-Araujo
mesh_terms: D000125:Achilles Tendon / Q000187:drug effects* / Q000201:enzymology* / Q000503:physiopathology; D045930:Anabolic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000704:Analysis of Variance; D000728:Androgens / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D015415:Biomarkers / Q000097:blood; D003345:Corticosterone / Q000032:analysis / Q000097:blood; D004195:Disease Models, Animal; D004789:Enzyme Activation / Q000187:drug effects; D018093:Gelatinases / Q000187:drug effects / Q000378:metabolism; D008297:Male; D020782:Matrix Metalloproteinases / Q000187:drug effects* / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000187:drug effects / Q000378:metabolism; D010805:Physical Conditioning, Animal; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D013256:Steroids / Q000008:administration & dosage / Q000494:pharmacology*; D013314:Stress, Mechanical
chemical_list: D045930:Anabolic Agents; D000728:Androgens; D015415:Biomarkers; D013256:Steroids; D010447:Peptide Hydrolases; D018093:Gelatinases; D020782:Matrix Metalloproteinases; D003345:Corticosterone