Ovulation in mammals
L’ovulation chez les mammifères
Résumé
The triggering of ovulation in mammals can be done according to two modes: spontaneous and provoked. Spontaneous ovulation occurs during the estrous cycle as a result of internal endocrine factors. Induced ovulation is triggered by mating. In both cases, it is the increase in GnRH secretion that leads to an increase in LH that causes ovulation. The factors involved in the stimulation of GnRH secretion are different according to the two modalities, mainly kisspeptin for spontaneous ovulators and beta-NGF for provoked ovulators. Current protocols used to induce ovulation rely on a direct action on the ovary, through the use of heterologous gonadotropins, or by an action on the pituitary gland with GnRH agonists. These protocols present different disadvantages: loss of activity with time, supra-physiological stimulation, ethic questioning about the production of some of these products. New paradigms for triggering ovulation by targeting the hypothalamus, respectful of animal welfare and the environment are presented in this review. This review aims to introduce the reader to the cellular and molecular mechanisms involved in the regulation and triggering of ovulation as well as two new approaches that are being developed and that are respectful of the animal and of its environment.
La maîtrise du moment de l’ovulation chez les mammifères d’élevage permet d’améliorer la fertilité, la gestion des mises bas, mais les méthodes actuelles sont basées sur l’utilisation de fortes doses d’hormones. Cette revue présente de nouveaux paradigmes pour maitriser le moment de l’ovulation, respectueux de la physiologie de l’animal, sans supplémentation hormonale basés sur la connaissance des mécanismes physiologiques.
Domaines
Sciences du Vivant [q-bio]
Origine : Fichiers éditeurs autorisés sur une archive ouverte
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