Avaliação por ultrassonografia doppler do efeito do extrato de pituitária equina em ovários de éguas cíclicas

Abstract

Aiming to evaluate the effect of crude equine pituitary extract (EPE), obtained during anestrous, on superovulation, and follicular and luteal vascularity, it was used six purebred Arabian mares in two estrous cycles (control and treatment). Mares were synchronized using prostaglandin F2α, and monitored daily by ultrasound B mode until the follicles reached diameter close to 23 mm (deviation). In this moment, mares in the treatment cycle received 8 mg of EPE, once a day, intramuscularly, until two or more follicles reached a diameter between 32 and 35 mm. Ovulation was induced with deslorelin acetate (750 mcg, MI) when follicles reached at least 35 mm. At the time of follicular deviation, induction of ovulation and final preovulatory exam, it was used B-mode ultrasound to measure the diameter of follicles, and, on the eighth day after ovulation, to measure the area of the corpus luteum (CL); color Doppler was also used to assess blood perfusion of the follicle wall and luteal parenchyma. In the control cycle was performed the same procedure except for the use of EPE. There was no effect of EPE on ovulation number, diameter of follicles, vascularity of the follicular wall and serum estrogen concentration. Animals treated or not, showed functional CLs, with no difference in parenchymal area or luteal vascularization, or in serum progesterone concentration on the eighth day after ovulation. It was observed that the EPE provided a greater number of subordinate follicles at the time of induction of ovulation of the dominant follicle. Although these follicles have failed to ovulate, it was concluded that EPE influenced the follicles growth, and it can be used in other biotechnologies, with greater utilization of equine ovarian follicular reserve.