ラット母児間のcharge barrierの局在

Near-term rats placentas were directly injected with two pairs of proteins differently charged. The placental localization of the proteins 60 min after the injection was determined by immunohistochemical staining and light microscopic autoradiography. Immunohistochemical studies (ie., immunofluorescence and immunoperoxidase studies) showed that there was no preferential localization in the placenta of native proteins injected. In contrast, cationized proteins injected were localized significantly in the Reichert's membrane. By light microscopic autoradiography, a large number of positive grains were found in the Reichert's membrane which is strongly positive for periodic acid-Schiff stain. And positive grains were also associated with trophoblast, parietal endoderm and visceral endoderm cells following the injection of cationized proteins. However, it is consistent with the immunohistochemical findings that positive grains were observed scarcely in the placenta when native proteins were injected. The present study suggest that Reichert's membrane in the rat may play an important role for the charge-dependent materno-fetal barrier since the rodent parietal yolk sac is well known to serve as a route via placenta.