ABSTRACT
El objetivo de este trabajo fue evaluar el efecto del tratamiento con hormona folículo estimulante (FSH) sobre la calidad y potencial de maduración in vitro (MIV) de ovocitos de gata. Veintiún gatas adultas fueron asignadas aleatoriamente a grupos de estudio. Grupo FSH (n = 9) 5 mg NIH/día de Foltropin-V por 4 días vía subcutánea y Grupo Control (n = 12) 1 mL de suero fisiológico por 4 días vía subcutánea. Los ovarios fueron obtenidos quirúrgicamente y transportados al laboratorio dentro de las 4 horas subsiguientes a 37°C. Los complejos cumulus-ovocito (CCOs) fueron obtenidos por rebanado ovárico, seleccionándose por criterios morfológicos aquellos considerados aptos para MIV. Se utilizó como medio de maduración TCM-199, BSA (0,4%), FSH (1µL/mL), LH (1µL/mL), 17beta estradiol (1µg/mL), gentamicina (50 µg/mL) y piruvato (0,2 mM). El cultivo se realizó durante 24 horas a 38,5°C con 5% de CO2. Posteriormente los ovocitos fueron denudados, fijados y teñidos para evaluar la maduración, considerándose maduros aquellos en metafase II. Se recuperaron en promedio por hembra 10,6 ± 3,6 y 7,1 ± 2,8 CCOs aptos para MIV en los grupos FSH y Control respectivamente (P <= 0,05). Se recuperó un 25,6% de CCOs aptos para MIV en el grupo FSH y 17% en el grupo Control (P <= 0,05). La tasa de MIV para el grupo FSH fue de un 73,6% versus 49,4% en el grupo Control (P <= 0,05). Se concluye que el tratamiento con FSH aumenta el número de CCOs aptos para MIV y que estos presentarían un mayor potencial de maduración.
The aim of this research was to evaluate the effect of Follicle Stimulating Hormone (FSH) treatment on quality and in vitro maturation potential of cumulus-oocyte complexes (COCs) recovered from domestic cats. Twenty-one mature cats were randomly assigned to two groups, FSH (n=9) and Control (n=12). Cats in FSH group were treated with 5 mg of Folltropin-V subcutaneously every 24 hours, for 4 consecutive days. Cats in Control group received 1 mL of sterile saline solution every 24 hours for 4 days. Ovaries were obtained surgically 24 hours after the end of the gonadotrophic treatment. Ovaries were then transported to the laboratory at 37°C within 4 hours after surgery. COCs were recovered by slicing, and classified according to morphological features. Maturation medium was based on TCM-199, and supplemented with 0.4% BSA, 1µL/mL FSH, 1µL/mL LH y 1µg/mL of 17ß oestradiol, 50 µg/mL gentamicin, 0.20 mM sodium pyruvate. The maturation period was of 24 hours under 38.5°C, 5% CO2 and saturated humidity. After this period oocytes were denuded, fixed and stained to asses their maturational status. Oocytes were considered mature when it was observed the presence of metaphase II plate and the expulsion of the first polar body. An average of 10.6 ± 3.6 and 7.1 ± 2.8 excellent and good quality COCs were recovered from cats in FSH and Control group respectively (P <= 0.05). Twenty five point six percent (25.6%) and 17% of recovered COCs from FSH and Control group respectively were classified as excellent or good (P <= 0.05). In vitro maturation rate was of 73.6% and 49.4% for the FSH group and the control group respectively (P <= 0.05). It can be concluded that FSH treatment increases the number of excellent and good quality oocytes obtained from cats and that these oocytes present a higher in vitro maturation potencial.