Presence of angiotensin II and expression of angiotensin II type-2 receptor in human fallopian tube

Objective: To determine the presence of angiotensin II and angiotensin II type-2 receptor subtype messenger RNA (mRNA) in human fallopian tube. Design: Frozen fallopian tubes were used for all studies. Setting: Procedures were performed at the Institute of Maternal and Child Research, School of Medicine, University of Chile and San Borja-Arriarán Clinical Hospital, National Health Service, Santiago, Chile. Patient(s): Eight patients (30–38 years) undergoing surgical sterilization or hysterectomy for benign gynecologic conditions. Intervention(s): Surgery was scheduled in the proliferative or secretory stage of the menstrual cycle. Main Outcome Measure(s): Localization of angiotensin II by immunofluorescence studies, expression of angiotensin II type-2 receptor mRNA, and concentrations of angiotensin II receptor subtypes and binding characteristics. Result(s): Angiotensin II was immunolocalized mainly in blood vessel endothelium and, to a lesser extent, in stromal cells. Both binding and angiotensin II type-2 receptor mRNA were detected at high levels. No differences were seen in receptor concentration, dissociation constants or median inhibitory concentration in fallopian tubes ipsilateral or contralateral to the corpus luteum. Conclusion(s): Angiotensin II and angiotensin II receptor are present in human fallopian tube. Angiotensin II type-2 receptor was the main receptor subtype. These results suggest that the renin-angiotensin system may play a regulatory role in functions of the fallopian tube.