Endothelin-2 in ovarian follicle rupture.
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.
Ko
Chemyong
C
Department of Clinical Sciences, University of Kentucky, Lexington, 40536, USA. cko2@uky.edu
Gieske
Mary C
MC
Al-Alem
Linah
L
Hahn
Yunkyung
Y
Su
Wen
W
Gong
Ming C
MC
Iglarz
Marc
M
Koo
Yongbum
Y
D000818:Animals; D019332:Endothelin-1 / Q000502:physiology; D019333:Endothelin-2 / Q000235:genetics / Q000502:physiology*; D019334:Endothelin-3 / Q000502:physiology; D047628:Estrogen Receptor alpha / Q000502:physiology; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology; D006080:Ovarian Follicle / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D017466:Receptors, Endothelin / Q000502:physiology
D019332:Endothelin-1; D019333:Endothelin-2; D019334:Endothelin-3; D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D017466:Receptors, Endothelin