Renin in the uterus of non-pregnant mice. Immunocytochemical, ultrastructural and biochemical studies.

The distribution of renin in the uterus of non-pregnant mice was studied by immunocytochemistry, using the peroxidase-antiperoxidase (PAP) technique, by electron microscopy and biochemical renin estimation. By immunocytochemistry, two separate localizations of renin could be identified, one in the apical region of the endometrial cells, the other in perivascular cells of the myometrium. The renin concentration in the endometrium, as determined cytochemically, and the total renin content of the uterus, as estimated enzymatically, varied with the ovarian cycle, being highest during the oestrus and lowest during the post-oestrus phase. The electronmicroscopic finding of the fluctuations in the granule content of the epithelial cells was in accordance with the immunocytochemical and biochemical data.