Compensation mechanisms for experimental reduction of the capacity in the guinea pig placenta
Abstract
After experimental reduction of its functional capacity the labyrinthine part of the placenta of the guinea pig has been studied microscopically for changes in the trophoblast and vascularization pattern, which could be interpreted as compensation for this reduction. In the experimental groups the volume density of fetal capillaries was increased significantly compared with untreated controls. The surface density of these vessels remained the same. The volume density of the maternal lacunae did not change significantly. No decrease of the thickness of the maternofetal barrier could be measured, nor did enlargement by microvilli of the apical and basal surface of the syncytium change significantly. The conclusion is that after experimental reduction of its functional capacity no pronounced structural modification in the guinea pig placenta occurs, which can be interpreted as a compensation mechanism.