title: Epidermal growth factor and active caspase-3 expression in the levator ani muscle of dogs with and without perineal hernia.
abstract: OBJECTIVE
  To perform a histological and immunohistochemical study of epidermal growth factor, transforming growth factor-alpha and their receptor, as well as the apoptotic signal active caspase-3 in the levator ani muscle of dogs with and without perineal hernia.
  
  
  METHODS
  Biopsy specimens of the levator ani muscle were obtained from 25 dogs with perineal hernia and 4 non-affected dogs and were processed for Masson and immunohistochemical staining.
  
  
  RESULTS
  The affected dogs exhibited myopathological features, internalised nuclei, destruction and abnormal size of muscle fibres, which were replaced by collagen. The immunohistochemical study revealed active caspase-3, epidermal growth factor, transforming growth factor-alpha and epidermal growth factor receptor in the levator ani. Compared to the healthy muscle, transforming growth factor-alpha staining intensity was lower in the affected muscle, whereas epidermal growth factor receptor and active caspase-3 staining were higher.
  
  
  CONCLUSIONS
  Pelvic diaphragm muscle weakening is the leading cause of perineal hernia in the dog. Survival and death signals expressed in these muscles may contribute to the pathogenesis of this disease. This study reports epidermal growth factor, transforming growth factor-alpha and epidermal growth factor receptor immunohistochemical expression in the skeletal muscle and suggests that perineal hernia in the dog is accompanied by levator ani muscle atrophy, increased expression of epidermal growth factor receptor, caspase-3 activation, and decreased expression of transforming growth factor-alpha.
authors.affiliation: Department of Animal Medicine and Surgery, Hospital Clínico Veterinario, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: J F
authors.initials: JF
authors.lastname: Pérez-Gutiérrez
authors.forename: J C
authors.initials: JC
authors.lastname: Argüelles
authors.forename: M
authors.initials: M
authors.lastname: Iglesias-Núñez
authors.forename: K S
authors.initials: KS
authors.lastname: Oliveira
authors.forename: M Sánchez
authors.initials: MS
authors.lastname: De La Muela
mesh_terms: D000818:Animals; D053148:Caspase 3 / Q000378:metabolism*; D004283:Dog Diseases / Q000378:metabolism* / Q000473:pathology; D004285:Dogs; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D006547:Hernia / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D010502:Perineum / Q000473:pathology; D016211:Transforming Growth Factor alpha / Q000378:metabolism
chemical_list: D016211:Transforming Growth Factor alpha; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D053148:Caspase 3