title: Effect of LED red and IR Photobiomodulation in tongue mast cells in Wistar rats: histological study.
abstract: OBJECTIVE
  This article aimed to study the effect of LED Phototherapy (LED-PHT) (?630?nm or ?850?nm) on mast cells on the dorsum of the tongue of rodents.
  
  
  BACKGROUND
  Vasodilatation is one of the reported effects of laser light on tissues. Laser light is able to induce the release of mediators responsible for vasodilatation, such as those produced by mast cells. Mast cells are also related to some diseases such as hay fever.
  
  
  METHODS
  Sixty Wistar rats were divided into three groups: I, Control; II, IR-LED (?850?nm, 21.9?J/cm(2), 73 sec; and III, red-LED (?630?nm, 21.9?J/cm(2), 73?sec). The specimens were taken after, 20, 45, and 60?min following irradiation. The specimens were routinely processed; stained with toluidine blue; and then total, degranulated, and non-degranulated mast cells were counted and statistical analysis performed.
  
  
  RESULTS
  Both LED irradiated subjects showed significant difference when compared to the control subjects on the total number mast cells (p<0.001, ANOVA), degranulated mast cells (p<0.001, ANOVA), and non-degranulated mast cells (p<0.001, ANOVA). Comparing the two groups of LED irradiated subjects, significant difference was observed regarding the total number of cells (p<0.001, paired t-test) and degranulated mast cells (p<0.001, paired t-test) with a greater number of these cells noted in the IR-LED group. On the other hand, Red-LED irradiated subjects showed a significantly greater number of non-degranulated mast cells (p=0.001, paired t-test).
  
  
  CONCLUSIONS
  Our results lead us to conclude that both red and IR-LED light caused increased mast cell degranulation and that IR-LED light resulted in a greater number of mast cells.
authors.affiliation: Center of Biophotonics, School of Dentistry, Federal University of Bahia, Salvador, Brazil.
authors.forename: Juliana Santos
authors.initials: JS
authors.lastname: de Carvalho Monteiro
authors.forename: Susana Carla Pires Sampaio
authors.initials: SC
authors.lastname: de Oliveira
authors.forename: Maria
authors.initials: M
authors.lastname: de F Tima Ferreira Lima
authors.forename: Jos Augusto Cardoso
authors.initials: JA
authors.lastname: Sousa
authors.forename: Ant Nio Luiz Barbosa
authors.initials: AN
authors.lastname: Pinheiro
authors.forename: Jean Nunes
authors.initials: JN
authors.lastname: Dos Santos
mesh_terms: D000818:Animals; D007259:Infrared Rays; D007834:Lasers; D008027:Light; D008297:Male; D008407:Mast Cells / Q000473:pathology / Q000528:radiation effects*; D051381:Rats; D017208:Rats, Wistar; D014059:Tongue / Q000166:cytology