The ovulatory process is activated by a surge of LH, a pituitary gonadotropin, which initiates a cohort of dramatic changes in biochemical, physical, and gene expression in the ovary, leading to follicle rupture and oocyte release. Here we report the identification of endothelin-2 (EDN2) as a last moment-trigger of follicle rupture. In the ovary, EDN2 is exclusively and transiently expressed in the granulosa cells immediately before ovulation. Administration of EDN2 to the ovarian tissue induced rapid contraction, whereas addition of tezosentan, an endothelin receptor antagonist, diminishes the EDN2 effect. In vivo, treatment of tezosentan before ovulation substantially decreases gonadotropin-induced superovulation. As a target tissue of EDN2 action, we identified a layer of smooth muscle cells in the follicular wall of each follicle. Taken together, our data indicate that EDN2 induces follicular rupture by constricting periovulatory follicles.
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http://dx.doi.org/10.1210/en.2005-1228 | DOI Listing |
Biol Res
October 2024
Department of Veterinary Surgery and Animal Reproduction, School of Veterinary Medicine and Animal Science, São Paulo State University (UNESP), Rua Prof. Doutor Walter Mauricio Correa, s/n, Botucatu, São Paulo, 18618-681, Brazil.
Background: There are many gaps in our understanding of the mechanisms involved in ovarian follicular development in cattle, particularly regarding follicular deviation, acquisition of ovulatory capacity, and preovulatory changes. Molecular evaluations of ovarian follicular cells during follicular development in cattle, especially serial transcriptomic analyses across key growth phases, have not been reported. This study aims to address this gap by analyzing gene expression using RNA-seq in granulosa and antral cells recovered from ovarian follicular fluid during critical phases of ovarian follicular development in Holstein cows.
View Article and Find Full Text PDFCommun Biol
October 2024
Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
During ovulation, the apical wall of the preovulatory follicle breaks down to facilitate gamete release. In parallel, the residual follicle wall differentiates into a progesterone-producing corpus luteum. Disruption of ovulation, whether through contraceptive intervention or infertility, has implications for women's health.
View Article and Find Full Text PDFIn Brief: Ovulation, the female reproductive process whereby fertilizable oocytes are released from a mature ovarian follicle, is widely seen in all animals that sexually reproduce. This paper reveals that, despite the remarkably diverse styles of ovulation among animal taxa, most ovulate via follicle rupture and suggests that the rupture process may operate via similar cellular mechanisms across animals.
Abstract: Ovulation is the process by which a fertilizable oocyte is extruded from the interior of the follicle.
Nat Cell Biol
November 2024
Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
During ovulation, an egg is released from an ovarian follicle, ready for fertilization. Ovulation occurs inside the body, impeding direct studies of its progression. Therefore, the exact mechanisms that control ovulation have remained unclear.
View Article and Find Full Text PDFCureus
August 2024
Department of Neuropathology, Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suárez, Mexico City, MEX.
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