Apoptosis as a basic mechanism in the ovarian cycle: follicular atresia and luteal regression.
OBJECTIVE
We summarized general principles related to apoptosis and reviewed the current evidence regarding apoptosis in the normal ovary during follicular atresia, ovulation, and corpus luteum formation and regression, and in the polycystic ovary.


METHODS
Published articles and abstracts from national scientific meetings were reviewed.


RESULTS
Apoptosis is a physiologic type of cell death that may regulate tissue remodeling. In the ovary, apoptosis occurs in atretic follicles, in the ovarian epithelium at the time of ovulation, and in the corpus luteum. Certain apoptosis-related genes are expressed during follicular atresia, which suggests a role for genes in the regulation of apoptosis in the ovary. In a rat model of polycystic ovaries, apoptosis occurs in both atretric follicles and cysts.


CONCLUSIONS
Apoptosis is an important physiologic process in the ovary, and abnormalities in this process may lead to pathologic conditions. The study of ovarian apoptosis is still at an early stage, and further research will uncover the steps in this process.
Palumbo
A
A
Department of Obstetrics, Gynecology, and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Yeh
J
J
D000818:Animals; D017209:Apoptosis; D053938:DNA Fragmentation; D005260:Female; D005496:Follicular Atresia / Q000502:physiology*; D006801:Humans; D003341:Luteolysis / Q000502:physiology*; D008597:Menstrual Cycle / Q000502:physiology*; D010053:Ovary / Q000166:cytology* / Q000502:physiology*; D011085:Polycystic Ovary Syndrome / Q000473:pathology / Q000503:physiopathology*; D051381:Rats