Generation of angiotensin I by tissues of the human female genital tract.

Tissues from the fetoplacental unit were incubated in medium E 199 at 0 degrees C and following removal of the tissue were incubated at 37 degrees C. Compared to control tissues held at 0 degrees C, large quantities of angiotensin I, measured by means of specific radioimmunoassay, were detected in the media from both amnion and chorion-decidua while only small amounts were found in the media from placenta and umbilical cord. Following prior incubation with antirenin, the generation of angiotensin I was abolished in all tissues. These results indicate that both renin and its substrate are released into the media during incubation at 0 degrees C and suggest the existence of a locally functioning renin-angiotensin system in certain tissues of the human female genital tract.