THE CYSTIC-FIBROSIS TRANSMEMBRANE REGULATOR GENE IS EXPRESSED IN THE HUMAN ENDOCERVIX THROUGHOUT THE MENSTRUAL-CYCLE

Objective: To measure cystic fibrosis transmembrane regulator (CFTR) g ene expression in cervical secretions during the menstrual cycle. Desi gn: Prospective, descriptive clinical study. Setting: University medic al center and affiliated outpatient office. Patients: Thirteen healthy women with ovulatory menstrual cycles. Interventions: Endocervical ce lls and secretions were obtained by cytobrushings during the midfollic ular, midcycle, and luteal phases. The cells were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) for CFTR and glyceral dehyde S-phosphate dehydrogenase (GAPDH) gene expression. Main Outcome Measures: Detection of CFTR gene expression and a quantitative compar ison of the levels of CFTR to GAPDH gene expression. Results: All endo cervical samples exhibited some degree of CFTR gene expression through out the menstrual cycle; however, the levels of expression were variab le. Cystic fibrosis transmembrane regulator gene expression did not co rrelate with E(2) or P levels. Conclusion: The production of copious c ervical secretions at the time of ovulation in part may be because of the transport of sodium and water across endocervical cell membranes a s a result of E(2)-stimulated CFTR mRNA and protein. Although cervical mucus becomes thick and scant during the luteal phase, CFTR gene expr ession is present in these secretions. (C) 1997 by American Society fo r Reproductive Medicine.