大部分萎縮卵細胞牽涉複雜之自我衰亡機轉

女性出生時卵巢擁有50萬個卵細胞，終其一生，女性只排出400個卵子
大部分卵細胞在分化過程中自我萎縮衰亡‧
其中牽涉複雜之自我衰亡(apoptosis)機轉與分生訊號

http://humrep.oxfordjournals.org/content/18/12/2678.full

Figure 4. Localization of DNA nuclear fragmentation (TUNEL positive) in oocyte and granulosa cells in primordial and primary follicles of human ovarian cortex. Original magnification ×400.

Evidence of apoptosis in human primordial and primary follicles

1. Raffaella Depalo1,3, 
2. Luigi Nappi1, 
3. Giuseppe Loverro1, 
4. Stefano Bettocchi1,
5. Maria Lucia Caruso2, 
6. Anna Maria Valentini2 and 
7. Luigi Selvaggi1

+Author Affiliations

1. ¹Department of General and Specialist Surgery, Gynaecology and Obstetric Unit A, University of Bari, Piazza Giulio Cesare, 11‐70124 Bari and
2. ²Department of Pathology, IRCCS ‘De Bellis’, Castellana Grotte (Bari), Italy

1. 3To whom correspondence should be addressed. e‐mail: rdepalo@iqsnet.it

• Received October 1, 2002.
• Revision received June 11, 2003.
• Accepted September 8, 2003.

 

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Abstract

BACKGROUND: Apoptosis may operate the ‘selection’ between follicles destined for atresia and follicles that will remain available for ovulation. The aim of this study is to assess the expression of apoptosis in quiescent follicles. METHODS: Ovarian cortex samples from women of reproductive age, fixed in formalin, were used for immunohistochemical and terminal deoxynucleotidyl transferase‐mediated deoxy‐UTP nick end labelling (TUNEL) methods. In histological sections the follicles were classified as primordial, primary, secondary and antral. Follicle density was defined as the total number of follicles/0.5 cm² of ovarian cortical tissue. Mab DO‐7 (anti‐p53) and Mab 124 (anti‐bcl‐2) were used in the immunohistochemical study. RESULTS: TUNEL was positive in 23.4% of the primordial follicles, and in 23.2% of the primary follicles, both in oocytes and granulosa cells, whereas all secondary follicles were negative. Bcl‐2 activity was expressed in 75% of secondary follicles. p53 was negative in all samples. CONCLUSIONS: Apoptosis could be the process responsible for atresia of quiescent follicles and hence depletion of the ovarian germ stockpile. Follicular cells expressing Bcl‐2 may therefore be the viable cells that escape the apoptotic process. Negative p53 patterns may be a favourable prognostic finding showing genome integrity in the replicating follicular cells of women of reproductive age.