13 Ultrastructure of Placental Tissue after 6H of Dual In Vitro Placenta Perfusion

Background: The dual in vitro placenta perfusion model allows the separated ex vivo perfusion of the maternal & fetal circulation and the investigation of the different functions of the placenta. The vitality and integrity of the perfused tissue up to the end of the perfusion experiment is essential for valid experiments. There is no systematic study about the ultrastructural integrity of the perfused placental tissue. Aim of the investigation: Estimation of placental ultrastructural intergrity after 6h of perfusion for extended evaluation of the dual in vitro placenta perfusion model using electron microscopy.Methods: Placentas (n=10) after uncomplicated pregnacies at term, the mothers gave their written informed consent. Sampling of villous tissue before and after 6h of dual in vitro placenta perfusion and deposition in fixation buffer. Preparation of semithin and ultrathin sections. Systematic investigation of the substructures rough and smooth endoplasmatic reticulum (ER), mitochondrium, nucleus, mikrovilli of syncytio- and cytotrophoblast by a blinded investigator. Control parameters for placental function: glucose consumption, lactat production, creatinine- and antipyrin permeability as well as leptin- and hCG release.Results: We found no significant differences of the substructures before and after 6h of dual in vitro placenta perfusion with stable placental function (constant glucose consumption and hormone release). We found in perfusion experiments with poor placental function (glucose consumption <0,1μmol/min/g, feto-maternal leakage) a distended rough ER and swelling of the mitochondria in syncytio- and cytotrophoblasts.Conclusion: 6h of dual in vitro placenta perfusion preserves the integrity of the cellular substructures. The used function parameters are correlated with substructural changes and they are therefore appropiate control parameters for vitality and integrity of the placental tissue.