Submitted September 28, 2007
Returned for revision November 5, 2007
Accepted April 14, 2008
Ovary
Intrafollicular Steroids and Anti-Müllerian Hormone During Normal and Cystic Ovarian Follicular Development in the Cow
Danielle Monniaux *,
Nathalie di Clemente ,
Jean-Luc Touzé ,
Corinne Belville ,
Charlène Rico ,
Martine Bontoux ,
Jean-Yves Picard ,
and
Stéphane Fabre
* To whom correspondence should be addressed. E-mail: monniaux{at}tours.inra.fr.
Abstract
Development of follicular cysts is a frequent ovarian dysfunction in cattle. Functional changes that precede cyst formation are unknown, but a role of anti-Müllerian hormone (AMH) in development of follicular cysts has been suggested in human. This study aimed to characterize intrafollicular steroids and AMH during follicular growth, in a strain of beef cows exhibiting a high incidence of occurrence of follicular cysts. Normal follicular growth and cyst development were assessed by ovarian ultrasonography scanning during 8 days before slaughtering. Experimental regression of cysts was followed by rapid growth of follicles that reached the size of cysts within 3 to 5 days. These young cysts exhibited higher intrafollicular concentrations of testosterone, estradiol-17beta and progesterone, but similar concentration of AMH, than large early dominant follicles on normal ovaries. Later stage cysts were characterized by hypertrophy of theca interna cells, high intrafollicular progesterone concentration and high STAR mRNA expression in granulosa cells. Progesterone and AMH concentrations in the largest follicles (
10 mm) and cysts were negatively correlated (r = -0.45, p <0.01). Smaller follicles (<10 mm) exhibited higher intrafollicular testosterone and estradiol-17beta concentrations in ovaries with cysts compared to normal ovaries. During follicular growth, AMH concentration dropped in follicles larger than 5 mm diameter, in a similar way in ovaries with and without cysts. In conclusion, enhanced growth and steroidogenesis in antral follicles <10 mm preceded cyst formation in cow ovaries. Intrafollicular AMH would not be a marker of cystic development in cow, but low AMH concentrations in cysts were associated with luteinization.
Key words:
Ovary •
Follicle •
Follicular development •
Steroid hormones •
Anti-Müllerian Hormone
