title: Immunohistochemical assessment of myofibroblasts and lymphoid cells during wound healing in rats subjected to laser photobiomodulation at 660 nm.
abstract: OBJECTIVE
  The goal of this study was to assess the biomodulatory effect of low-level laser therapy (LLLT) on myofibroblasts and T and B cells during wound healing.
  
  
  BACKGROUND
  Phtotobiomodulation using LLLT has been extensively applied to improve wound healing.
  
  
  METHODS
  Standardized artificial surgical wounds were made on the backs of 24 male rats. Half of them underwent LLLT (20 J/cm(2)) at 660 nm delivered for 7 d. At 8 and 14 d post-surgery the healing wounds were removed and immunohistochemical analysis of myofibroblasts, T cells, and B cells was carried out. The mean of each cell subset was calculated and compared to one another using two-way analysis of variance (ANOVA) and Tukey's test.
  
  
  RESULTS
  The average number of myofibroblasts was statistically significantly higher in the irradiated group than in the non-irradiated group on the eighth (p = 0.001) but not the 14th (p = 0.555) day. B and T cells were significantly more conspicuous in the irradiated group on both the eighth (p = 0.004 and 0.02, respectively) and 14th days (p = 0.04 and 0.03, respectively).
  
  
  CONCLUSIONS
  Our results suggest that LLLT facilitates myofibroblastic differentiation during the early stages of the cicatricial repair process. Furthermore, LLLT also appears to modulate the inflammatory response by downregulating lymphocytic proliferation during the wound healing process.
authors.affiliation: Propedeutics and Integrated Clinics, Federal University of Bahia, School of Dentistry, Salvador, Bahia, Brazil. endoribeiro@yahoo.com.br
authors.forename: Maria Amalia Gonzaga
authors.initials: MA
authors.lastname: Ribeiro
authors.forename: Ricardo Luiz Cavalcanti
authors.initials: RL
authors.lastname: Albuquerque
authors.forename: Luciana Maria Pedreira
authors.initials: LM
authors.lastname: Ramalho
authors.forename: Antonio Luiz Barbosa
authors.initials: AL
authors.lastname: Pinheiro
authors.forename: Leonardo Rigoldi
authors.initials: LR
authors.lastname: Bonjardim
authors.forename: Samantha Seara
authors.initials: SS
authors.lastname: Da Cunha
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D005347:Fibroblasts / Q000166:cytology / Q000528:radiation effects*; D007150:Immunohistochemistry; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy; D008214:Lymphocytes / Q000528:radiation effects*; D008297:Male; D009130:Muscle, Smooth / Q000166:cytology / Q000528:radiation effects*; D051381:Rats; D017208:Rats, Wistar; D014945:Wound Healing / Q000528:radiation effects*