title: Low-level laser therapy promotes vascular endothelial growth factor receptor-1 expression in endothelial and nonendothelial cells of mice gastrocnemius exposed to snake venom.
abstract: Crotalinae snake venoms cause severe local myonecrosis and microvasculature failure at the bite site. We evaluated whether low-level laser therapy (LLLT) could accelerate angiogenesis and myoregeneration in male Swiss mice injected with Bothrops moojeni venom through immunohistochemistry of the vascular endothelial growth factor receptor-1 (VEGFR-1). Envenomed gastrocnemius was either unirradiated (V) or irradiated with HeNe (VHN, 632.8 nm) or GaAs (VGA, 904 nm, 10000 Hz). Animals sacrificed at 3 and 12 h were irradiated once (4 J cm(-2)), at 24 h (twice) and at 3, 7, 21 days (4, 8, 22 times, respectively). At 3 days, LLLT increased angiogenesis (80%:HeNe vs 40%:GaAs), decreased neutrophils and increased proliferation of regenerating cells. However, after 21 days, myoregeneration observed in the VHN group appeared delayed compared with the V group. As LLLT improved revascularization, the suggestive delay in myoregeneration could be a dose-response inhibitory effect caused by multiple irradiations in myogenesis. The immunodetection of VEGFR-1 in neutrophils, macrophages, satellite cells, fibroblasts, Schwann cells and skeletal and smooth muscle fibers (not seen in saline-controls) at only the acute stages of envenoming suggests a mediator role for VEGFR-1 in local alterations. This is the first time that VEGFR-1 expression, and its modulation by photostimulation, has been demonstrated in endothelial and nonendothelial cells of snake envenomed skeletal muscle.
authors.affiliation: Departmento de Histologia e Embriologia, Instituto de Biologia, Universidade Estadual de Campinas-UNICAMP, Campinas, SP, Brazil.
authors.forename: Doroty M
authors.initials: DM
authors.lastname: Dourado
authors.forename: Sílvio
authors.initials: S
authors.lastname: Fávero
authors.forename: Rosemary
authors.initials: R
authors.lastname: Matias
authors.forename: Paulo de Tarso C
authors.initials: Pde T
authors.lastname: Carvalho
authors.forename: Maria Alice
authors.initials: MA
authors.lastname: da Cruz-Höfling
mesh_terms: D000818:Animals; D017837:Bothrops; D049109:Cell Proliferation; D003435:Crotalid Venoms / Q000494:pharmacology*; D042783:Endothelial Cells / Q000166:cytology*; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D028022:Low-Level Light Therapy; D008297:Male; D051379:Mice; D018482:Muscle, Skeletal / Q000187:drug effects*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism*
chemical_list: D003435:Crotalid Venoms; D040281:Vascular Endothelial Growth Factor Receptor-1