Papel del plasma seminal en el control de la inflamación endometrial postinseminación en équidos

Abstract

Donkeys (Equus asinus), are a species of wild origin, surely the first to be domesticated by man. For centuries it was indispensable in the tasks of the field, but mechanization almost led to its disappearance. Today, the importance of this species has grown again thanks to the interest of its use in new fields. As a consequence, interest in donkey breeding has increased in recent years._x000D_ _x000D_ The induction of fertile ovulations is essential for the application of these reproductive technologies and their improvement. In the first work of this thesis, it is proposed to use Color Doppler ultrasound as an instrument to control the vascularization of the jennies’ corpus luteum and thus be able to determine the best time to administer PGF2a and induce luteolysis that occurs between 3 and 5 hours. after the application of a prostaglandin and is the result of an ischemia of the corpus luteum with the consequent loss of functionality of the corpus luteum and a decrease in plasma progesterone levels. Artificial insemination (AI) of jennies with frozen-thawed donkey semen is associated with low fertility rates. The addition of seminal plasma (SP), eliminating during the freezing process, or the increase in sperm concentration, have shown a certain increase in these pregnancy rates. On the other hand, in the jenny an exaggerated inflammatory response was observed a few hours after insemination, possibly related to low fertility. Previous studies have analyzed this response by recovering polymorphonuclear neutrophils (PMN) from post-AI uterine lavages. However, repetition of these washes can adversely affect the endometrium and lead to fertility problems. For this reason, in the second article, a set of experiments has been carried out to establish an in vitro model by collecting PMN from the peripheral blood of jennies, testing how the concentration of sperm affects their interaction with PMN. A valid model has been obtained to be able to recreate in vitro the physiological conditions that occur in vivo. It has been concluded that the SP has the capacity to activate the PMN. On the other hand, little sperm phagocytosis has been observed while most of these appear attached to the surface of the PMN or in a surrounding halo. Likewise, a good part of these are kept alive, with an intense tail movement and, in concentrations above 500x106, some can be released with excellent mobility after 3h incubation at 37ºC._x000D_ _x000D_ The role of SP appears to be very important in modulating this physiological inflammation of jennies. To facilitate their study, the objective of the third experiment was to fractionate donkey seminal plasma based on the molecular weight of proteins and to analyze the effect on spz motility and PMN: spz interaction. From the SP of five donkeys, 6 fractions ( 10 kDa) were obtained, which were contacted with a PMN: spz solution and incubated at 37ºC. . At 1h, 2h, 3h, 4h, sperm motility was evaluated with the CASA system (ISAS®), the viability of the sperm using an eosinigrosin stain and the PMN: spz interaction using a triple Diff-QuikR stain._x000D_ _x000D_ SP fractions including proteins between 30-50 kDa and 50-100kDa showed the best maintenance of the mobile sub-populations of donkey spz as well as are involved in the control of the jennies’ post-AI inflammatory response. Several proteins involved in fertilization have a molecular weight between 30 and 100 kDa.

Date of Award	2 Oct 2020
Original language	Spanish
Supervisor	Jordi Miro Roig (Director)