ALTERATIONS IN THE SUBCELLULAR-DISTRIBUTION OF 17-BETA-ESTRADIOL DEHYDROGENASE IN PORCINE ENDOMETRIAL CELLS OVER THE COURSE OF THE ESTROUS-CYCLE

The uteri of German landrace gilts slaughtered at different days of th e cycle were processed for immunocytochemistry and biochemical analyse s. Plasma was collected for hormone assays. The monoclonal antibody F1 against the structure-bound 17 beta-estradiol dehydrogenase of porcin e endometrial epithelium was applied to rehydrated paraffin sections e ither as a direct, peroxidase-linked probe or in combination with a fl uorescing secondary antibody. The oxidation of estradiol was measured in homogenates of tissue powdered in liquid nitrogen. Immunoreactivity was restricted to endometrial epithelium. In the glandular epithelium , faint dots of fluorescence became visible at day 4, which apparently coalesced to spherical structures of 2-4 mu m diameter at the cell ba sis between days 11 through 17 before disappearing by day 18. A simila r distribution was observed for the oxidation products of diaminobenzi dine beginning with a faint uniform staining and followed by the appea rance of intensely stained basal bodies persisting until day 17. Essen tially the same time course was seen in the luminal epithelium but wit h a different distribution. Immunoreactive material amassed in the api cal region of the cells, but the conspicuous aggregations were absent. Time course and intensities of the immunological responses are matche d by the enzymatic activity measured in parallel. Both correlate with the plasma progesterone levels, suggesting an induction of the enzyme by the hormone. An involvement of the cytoskeleton in the sequence of subcellular distribution patterns is discussed.