Localisation immunohistochimique de l’enzyme 5α-réductase type 1 et 3 dans la peau et la prostate de chiens beagle en santé
The 5α-reductase isoenzymes (5αR) are responsible for the conversion of testosterone into DHT. Recently, we reported the presence of mRNA for 5α-reductases in canine skin. Although we detected mRNA encoding 5αR1 and 5αR3 but not 5αR2, the distribution and localization of 5αR isoenzymes throughout the canine skin and hair follicle are still unknown. The objectives of this study were therefore to demonstrate the specific distribution and localization of 5αR type 1 and 3 isoenzymes in the skin, hair follicle and prostate of healthy beagle dogs by immunohistochemistry. Eight healthy, unrelated and intact young-mature beagle dogs (4 males and 4 females) with no history of skin disease were selected for this study. Skin biopsy samples were obtained from three anatomic sites normally affected by alopecia X (dorsal neck, back of thighs and base of tail) and two sites generally unaffected (dorsal head and ventral thoracic regions). Canine prostate glands (n=3) also collected. In the prostate gland, 5αR1 was present in secretory epithelial cells, basal epithelial cells and blood vessels. On the other hand, 5αR3 was present in basal epithelial cells and blood vessels, but was not detected in secretory epithelial cells. In the skin, 5αR1 was detected in anagen hair follicle at the level of connective tissue sheath, outer and inner root sheath, hair shaft, and dermal papilla. It was also detected in the sebaceous and sweat glands, arrector pili muscles and in vascular endothelial cells. The 5αR3 protein was detected in connective tissue sheath, dermal papilla and vascular endothelial cells of anagen hair follicles. To our knowledge, this is the first study describing the specific localization of 5αR1 and 5αR3 isoenzymes in normal canine skin, hair follicles and prostate of normal healthy beagle dogs.
Prostate Alopecia X 5α-reductase isoenzymes 5α-reductase type 1 5α-reductase type 3 Immunohistochemistry Skin