title: Are excessive granulation tissue formation and retarded wound contraction due to decreased collagenase activity in wounds in tight-skin mice?
abstract: Wound contraction is delayed in tight-skin mice but the mechanism(s) are unknown. The purpose of this study was to investigate collagenase levels and the formation of granulation tissue in experimental wounds in tight-skin mice. One full-thickness skin excision (20 x 20 mm) was made on the back of nine tight-skin and eight normal mice. Granulation tissue analyses were performed 7 days post-operatively. The collagenase activity was determined by the use of a radiolabelled telopeptide-free collagen substrate, and the amount of granulation tissue was determined gravimetrically. Wound contraction was delayed (P < 0.001) in tight-skin mice (mean 22%) compared with normal mice (mean 46%). The collagenase activity was decreased (P < 0.05) by 40%, whereas the quantity of granulation tissue was increased (P < 0.001) by 60% in the wounds of tight-skin mice. Decreased collagenase content may provide one explanation for the delayed contraction of full-thickness wounds in tight-skin mice. Furthermore, this animal would model may prove useful in the understanding of the pathogenesis, and in exploration of treatment, of excessive granulation tissue formation during wound healing.
authors.affiliation: Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, FL 33101.
authors.forename: M S
authors.initials: MS
authors.lastname: Agren
authors.forename: P M
authors.initials: PM
authors.lastname: Mertz
mesh_terms: D000818:Animals; D017364:Collagenases / Q000378:metabolism*; D006097:Granulation Tissue / Q000201:enzymology*; D051379:Mice; D008817:Mice, Mutant Strains; D012867:Skin / Q000293:injuries; D013997:Time Factors; D014945:Wound Healing
chemical_list: D017364:Collagenases