Nitric oxide induced cervical ripening in the human: Involvement of cyclic guanosine monophosphate, prostaglandin F(2 alpha), and prostaglandin E(2).
OBJECTIVE
The purpose of the study was to investigate possible mechanisms and morphologic changes involved in nitric oxide-induced cervical ripening.


METHODS
Women scheduled for surgical termination of first trimester pregnancy were randomized to 1 of 3 groups: isosorbide 5-mononitrate 40 mg 4 hours or 10 hours before the operation or no preoperative treatment. Cervical specimens were obtained for the analysis of tissue levels of cyclic guanosine monophosphate, cyclic adenosine monophosphate, cyclo-oxygenase 1, cyclo-oxygenase 2, prostaglandin F(2 alpha), and prostaglandin E(2) or were fixed in glutaraldehyde for microscopy.


RESULTS
Increased levels of cyclic guanosine monophosphate, cyclo-oxygenase 2, prostaglandin F(2 alpha), and prostaglandin E(2) were found in samples that were exposed to isosorbide 5-mononitrate compared with control samples. Electron microscopy revealed stromal edema and collagen disorganization after isosorbide 5-mononitrate treatment.


CONCLUSIONS
Cyclic guanosine monophosphate, prostaglandin F(2 alpha), and prostaglandin E(2) are involved in nitric oxide-induced cervical ripening. Nitric oxide causes morphologic changes similar to those changes seen during spontaneous cervical ripening.
Ekerhovd
E
E
Department of Obstetrics and Gynecology, Göteborg University, Sweden. erling.ekerhovd@obgyn.gu.se
Weijdegård
B
B
Brännström
M
M
Mattsby-Baltzer
I
I
Norström
A
A
D020070:Cervical Ripening; D002584:Cervix Uteri / Q000033:anatomy & histology / Q000737:chemistry / Q000187:drug effects; D000242:Cyclic AMP / Q000032:analysis; D006152:Cyclic GMP / Q000032:analysis / Q000502:physiology*; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015237:Dinoprost / Q000032:analysis / Q000502:physiology*; D015232:Dinoprostone / Q000032:analysis / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D015151:Immunoblotting; D007527:Isoenzymes / Q000032:analysis; D007548:Isosorbide Dinitrate / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D008565:Membrane Proteins; D008854:Microscopy, Electron; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000008:administration & dosage / Q000494:pharmacology; D011247:Pregnancy; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis
D007527:Isoenzymes; D008565:Membrane Proteins; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D015237:Dinoprost; D000242:Cyclic AMP; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D006152:Cyclic GMP; D007548:Isosorbide Dinitrate; D015232:Dinoprostone; C030397:isosorbide-5-mononitrate