Immunolocalization of androgen receptors, estrogen alpha receptors, and estrogen beta receptors in experimentally induced canine prostatic hyperplasia.

Benign prostatic hyperplasia (BPH) is an age-dependent prostatic disease affecting male humans and dogs. In dogs, the combined administration of estrogens and androgens synergistically increases prostate weight, and continued treatment leads to the development of glandular hyperplasia. The aim of the present study was to examine the immunohistochemical expression of androgen receptor (AR), estrogen receptor alpha (ER alpha), and estrogen receptor beta (ER beta) in the different cell types of the prostate gland in an experimental model. Five male beagle dogs were castrated and treated with 25 mg of 5 alpha-androstane-3 alpha and 17beta-diol and 0.25 mg 17beta-estradiol for 30 weeks. Prostate specimens were surgically obtained every 45 days (experimental stages M0 to M6: 0, 12, 18, 24, 30, and 36 weeks from the beginning of the hormonal treatment). The control group consisted of 3 noncastrated dogs treated with a vehicle, from which specimens were only taken at the time points M0, M1, M4, and M6. Immunohistochemical data revealed high AR and ER alpha expression in the epithelial and stromal cell nuclei of all the experimental and control specimens. Weak staining of the cytoplasm was observed only in epithelial cells. The suspension of hormone treatment led to a significant reduction in the expression of both receptors. On the contrary, ER beta was expressed only in epithelial cell nuclei, with no significant differences in the percentages of stained nuclei between control and hormonally treated or atrophic prostates. Results indicate that AR, ER alpha, and ER beta are differently expressed in canine prostate tissue and that they show specific expression patterns in response to the hormonal induction of BPH.

Determinación del protocolo de criopreservación de semen canino: reporte preliminar / Determination of the protocol for the criopreservation of the canine semen: preliminary report

Se recolectaron muestras de semen a 7 machos caninos de varias razas, a las cuales se les practicó un espermatograma completo. Aquellas muestras seminales clasificadas como óptimas fueron utilizadas para ser sometidas al proceso de criopreservación. Se procedió a congelar el semen utilizando un diluente a base de TRIS, ácido crítico, glucosa, penicilina, estreptomicina, yema de huevo, agua destilada y glicerol. El semen fue congelado en vapores de nitrógeno líquido a 10 centímetros por encima de su nivel. El semen fue sometido a pruebas de evaluación considerándose los parámetros de volumen, color, pH, motilidad, concentración y morfología. Se realizaron pruebas de resistencia térmica en placas calentadas para el semen fresco, diluido, glicerinado y descongelado, por períodos de tiempo de 15, 30, 45, 60 y 90 minutos, obteniéndoseresultados de motilidad de hasta 30% al cabo de 90 min. Se pudo observar la versatilidad y sensillez del uso de este dilutor y de la técnica de congelación en vapores de nitrógeno líquido para la criopreservación del semen canino.