Angiogenic and steroidogenic responses of the corpus luteum after superovulatory and stimulatory treatments using eCG and FSH
Fátima, L ABinelli, NBaruselli, P SBonfim Neto, A PPapa, P C
The corpus luteum (CL) is a pivotal organ for the success of reproductive function and a main target of assisted reproduction techniques. Moreover, increases in progesterone production and CL volume have been repeatedly reported after the use of exoge nous gonadotropins administered to improve the quality of the dominant follicle (stimulatory treatment) or to increase the number of ovulated follicles (superovulatory treatment). This review aims to discuss the CL-related molecular, cellular and ti ssue mechanisms associated with the improvement of reproductive performance achieved under superovulatory and stimulatory treatments in cattle. Here, we report that FSH (follicle stimulating hormone) but not eCG (equine chorionic gonadotropin) induce vascularization at the molecular level despite the increase in CL volume in response to both gonadotropins. Increases in plasma progesterone concentrations per CL in response to a stimulatory but not superovulatory treatment with eCG as well as cellular and molecular alterations that support luteal function are also reviewed. Whereas practitioners make use of hormonal protocols aiming to increase pregnancy rates, we focus our efforts on uncovering the cellular and molecular mechanisms that are triggered by such successful strategies, hoping our findings will contribute to the achievement of the next successful step.(AU)
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