An Investigation of the Cellular Source of Renin in Human Chorion

Summary An investigation has been made into the cellular source of renin in human chorion. Using cytogenetic techniques the cells producing renin in tissue cultures of chorion have been identified as fetal and not maternal in origin. Histochemical studies using the Bowie stain have shown the presence of cells containing Bowie‐positive granules in the cytoplasm in the spongy layer of amnion and the reticular layer of chorion. These cells do not occur in the trophoblastic layer and morphologically have been shown to resemble the Hofbauer cell. Chorion cells producing renin during in vitro culture do not, however, display Bowie‐positive cytoplasmic granules.