The expression of inducible nitric oxide synthase in the human fallopian tube during the menstrual cycle and in ectopic pregnancy.
OBJECTIVE
To investigate the production of inducible nitric oxide synthase (iNOS) in the fallopian tube (FT) during the menstrual cycle and whether epithelia from FTs bearing an ectopic pregnancy differ from healthy tubes in iNOS expression.


METHODS
Prospective study.


METHODS
Academic unit of reproductive and developmental medicine.


METHODS
Fallopian tubes from the different stages of the menstrual cycle (n=12), FTs bearing an ectopic pregnancy (n=15), and FTs from pseudopregnant women (n=6) were collected.


METHODS
In the pseudopregnant group, patients were injected with hCG in the days leading up to hysterectomy. Samples were processed for immunohistochemistry staining and quantitative reverse transcriptase polymerase chain reaction.


METHODS
To compare iNOS protein and messenger RNA expression between the different groups.


RESULTS
This is the first report on cyclicity in iNOS production by human fallopian tube during the menstrual cycle. The intensity of expression of iNOS was higher in the ectopic pregnancy group compared with the pseudopregnant group (P<0.05).


CONCLUSIONS
The cyclicity in iNOS expression by the tube suggests its involvement in fertilization and early embryonic development. Pathologic generation of nitric oxide through increase iNOS production may decrease tubal ciliary beats and smooth muscle contractions and thus affect embryo transport, which may consequently result in ectopic pregnancy.
Al-Azemi
Majedah
M
Academic Unit of Reproductive and Developmental Medicine, Royal Hallamshire Hospital, Sheffield, United Kingdom.
Refaat
Bassem
B
Amer
Saad
S
Ola
Bolarinde
B
Chapman
Neil
N
Ledger
William
W
D000328:Adult; D001692:Biological Transport / Q000235:genetics; D016022:Case-Control Studies; D004622:Embryo, Mammalian / Q000378:metabolism; D005187:Fallopian Tubes / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007150:Immunohistochemistry; D008597:Menstrual Cycle / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D052247:Nitric Oxide Synthase Type II / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D011555:Pseudopregnancy / Q000235:genetics / Q000378:metabolism / Q000473:pathology
D052247:Nitric Oxide Synthase Type II