title: Effects of tretinoin on wound healing in aged skin.
abstract: Aged and adult populations have differences in the structural, biological, and healing properties of skin. Comparative studies of healing under the influence of retinoids in both these populations are very important and, to the best of our knowledge, have not been performed to date. The purpose of this study was to compare the activities of topical tretinoin in aged and adult animal models of wound healing by secondary intention. Male aged rats (24 months old, n = 7) and adult rats (6 months old, n = 8) were used. The rats were assigned to the following groups according to the dates on which wound samples were excised (day 14 or 21 after model creation): treated group, control group, and naive group. Topical application of tretinoin cream was used only on the proximal wound and was applied daily for 7 days. Wound healing areas were measured using metal calipers, and morphological analysis was performed. Slides were stained with Hematoxylin and Eosin, Masson's trichrome, and periodic acid-Schiff stains. Statistical analysis adopted a 5% coefficient for rejection of the null hypothesis. Although aged animals showed skin repair, complete reepithelialization was found on day 21 in some animals of both groups (treated and control). In aged rats, the wound area was significantly smaller in treated wounds than in untreated wounds, resulting in a larger scar area compared with the adult group. When treated wounds were compared, no differences were found between the wound areas in adult and aged rats. As expected, the collagen concentration was higher in normal skin from adult rats than in normal skin from aged animals, but there was no difference when aged skin was treated with tretinoin. These results indicate that tretinoin increases collagen synthesis in aged skin and returns the healing process to a normal state of skin healing.
authors.affiliation: Sao Francisco University Medical School, Bragança Paulista, Sao Paulo, Brazil.
authors.forename: Danielle
authors.initials: D
authors.lastname: de Campos Peseto
authors.affiliation: Sao Francisco University Medical School, Bragança Paulista, Sao Paulo, Brazil.
authors.forename: Erica Vilaça
authors.initials: EV
authors.lastname: Carmona
authors.affiliation: Sao Francisco University Medical School, Bragança Paulista, Sao Paulo, Brazil.
authors.forename: Kellyn Cristina da
authors.initials: KC
authors.lastname: Silva
authors.affiliation: Sao Francisco University Medical School, Bragança Paulista, Sao Paulo, Brazil.
authors.forename: Flavia Roberta Valente
authors.initials: FR
authors.lastname: Guedes
authors.affiliation: Sao Francisco University Medical School, Bragança Paulista, Sao Paulo, Brazil.
authors.forename: Fernando
authors.initials: F
authors.lastname: Hummel Filho
authors.affiliation: Sao Francisco University Medical School, Bragança Paulista, Sao Paulo, Brazil.
authors.forename: Natalia Peres
authors.initials: NP
authors.lastname: Martinez
authors.affiliation: Sao Francisco University Medical School, Bragança Paulista, Sao Paulo, Brazil.
authors.forename: José Aires
authors.initials: JA
authors.lastname: Pereira
authors.affiliation: Sao Francisco University Medical School, Bragança Paulista, Sao Paulo, Brazil.
authors.forename: Thalita
authors.initials: T
authors.lastname: Rocha
authors.affiliation: Sao Francisco University Medical School, Bragança Paulista, Sao Paulo, Brazil.
authors.forename: Denise Gonçalves
authors.initials: DG
authors.lastname: Priolli
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism; D004195:Disease Models, Animal; D006097:Granulation Tissue / Q000378:metabolism; D007641:Keratolytic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D062326:Re-Epithelialization / Q000187:drug effects; D015595:Skin Aging / Q000187:drug effects* / Q000473:pathology*; D014212:Tretinoin / Q000494:pharmacology* / Q000627:therapeutic use*; D014945:Wound Healing / Q000187:drug effects*; D014947:Wounds and Injuries / Q000188:drug therapy* / Q000473:pathology
chemical_list: D007641:Keratolytic Agents; D014212:Tretinoin; D003094:Collagen