Article

Endothelin-2 in ovarian follicle rupture.

Department of Clinical Sciences, University of Kentucky, Lexington, 40536, USA.
Endocrinology (impact factor: 4.46). 05/2006; 147(4):1770-9. DOI:10.1210/en.2005-1228
Source: PubMed

ABSTRACT 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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Keywords

biochemical
 
dramatic changes
 
EDN2
 
EDN2 action
 
EDN2 effect
 
EDN2 induces follicular rupture
 
endothelin receptor antagonist
 
endothelin-2
 
follicle
 
follicle rupture
 
follicular wall
 
gene expression
 
granulosa cells
 
ovarian tissue induced rapid contraction
 
ovulation
 
ovulatory process
 
periovulatory follicles
 
pituitary gonadotropin
 
smooth muscle cells
 
transiently