title: Identification of 5α-reductase isoenzymes in canine skin.
abstract: BACKGROUND
  Alopecia X in dogs is a noninflammatory alopecia that may be caused by a hormonal dysfunction. It may be similar to androgenic alopecia in men that is caused by the effect of dihydrotestosterone (DHT). The 5α-reductase isoenzymes, 5αR1 and 5αR2, and a recently described 5αR3, are responsible for the conversion of testosterone into DHT. However, which 5α-reductases are present in canine skin has not yet been described.
  
  
  OBJECTIVE
  The main objective of this study was to determine the pattern of expression of 5α-reductase genes in canine skin.
  
  
  METHODS
  Skin biopsies were obtained from healthy, intact young-mature beagles (three males, four females) at three anatomical sites normally affected by alopecia X (dorsal neck, back of thighs and base of tail) and two sites generally unaffected (dorsal head and ventral thorax). Prostate samples (n = 3) were collected as positive controls for 5α-reductase mRNA abundance measurement by real-time PCR.
  
  
  RESULTS
  We detected mRNA encoding 5αR1 and 5αR3 but not 5αR2. There were no significant differences in 5αR1 and 5αR3 mRNA levels between the different anatomical sites, irrespective of gender (P > 0.05). Moreover, the mean mRNA abundance in each anatomical site did not differ between males and females (P > 0.05).
  
  
  CONCLUSIONS
  To the best of the authors' knowledge, this is the first study demonstrating the expression of 5α-reductases in canine skin and the expression of 5αR3 in this tissue. These results may help to elucidate the pathogenesis of alopecia X and to determine more appropriate treatments for this disorder.
authors.affiliation: Department of Veterinary Clinical Sciences, Faculté de Médecine Vétérinaire, de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Lucilene
authors.initials: L
authors.lastname: Bernardi de Souza
authors.affiliation: Department of Veterinary Clinical Sciences, Faculté de Médecine Vétérinaire, de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Manon
authors.initials: M
authors.lastname: Paradis
authors.affiliation: Centre de Recherche en Reproduction Animale, Faculté de Médecine Vétérinaire, de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Zamberlam
authors.affiliation: Department of Veterinary Pathology and Microbiology, Faculté de Médecine Vétérinaire, Université de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Marie-Odile
authors.initials: MO
authors.lastname: Benoit-Biancamano
authors.affiliation: Centre de Recherche en Reproduction Animale, Faculté de Médecine Vétérinaire, de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Christopher
authors.initials: C
authors.lastname: Price
mesh_terms: D000818:Animals; D001706:Biopsy / Q000662:veterinary; D042944:Cholestenone 5 alpha-Reductase / Q000032:analysis*; D004285:Dogs / Q000378:metabolism*; D005260:Female; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D012867:Skin / Q000201:enzymology*
chemical_list: D007527:Isoenzymes; D042944:Cholestenone 5 alpha-Reductase