Changes in the ratio of Bax and Bcl-2 mRNA expression and their cellular localization throughout the ovulatory cycle in the human oviduct.
OBJECTIVE
To examine changes in the ratio of Bax and Bcl-2 mRNA expression throughout the ovulatory cycle in the ampullary region of the human oviduct.


METHODS
The mucosal layer was isolated from the human oviduct tissue and semiquantitative reverse-transcriptase polymerase chain-reaction (RT-PCR) analysis of mRNA of Bax and Bcl-2 was performed. Immunohistochemistry provided the cellular localization of the Bax and Bcl-2 proteins. The ratio of expression of Bax and Bcl-2 mRNA was examined in the ampullary region of the oviduct in samples obtained in the follicular, periovulatory, and luteal phases of the ovulatory cycle.


RESULTS
Bax expression was constant in the follicular and periovulatory phase but showed a significant increase in the luteal phase. The Bax protein was present in all oviduct mucosal epithelial cells and the intensity of staining increased in luteal phase samples. Bcl-2 was expressed at a relatively constant level throughout the ovulatory cycle. The Bcl-2 protein was present in some but not all mucosal epithelial cells and the proportion of positive cells remained constant throughout the ovulatory cycle.


CONCLUSIONS
The proapoptotic gene Bax shows a significant increase in mRNA expression in the luteal phase of the ovulatory cycle while the expression level of the antiapoptotic gene Bcl-2 remains constant throughout the ovulatory cycle. The ratio of Bax:Bcl-2 increases significantly in the luteal phase consistent with cells undergoing apoptosis.
Briton-Jones
Christine
C
The Department of Obstetrics and Gynaecology, The Prince of Wales Hospital, Shatin, New Territories, Hong Kong, People's Republic of China.
Lok
Ingrid Hung
IH
Po
Alice Lai See
AL
Cheung
Che Kwok
CK
Chiu
Tony T Y
TT
Haines
Christopher
C
D017209:Apoptosis; D005187:Fallopian Tubes / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051028:bcl-2-Associated X Protein / Q000096:biosynthesis* / Q000378:metabolism*
D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein