Morphosis study on the permeability of the mesothelium of parietal pleura in rat

Objective To observe the permeability of parietal pleura and discuss the absorptive pathway of the particulates in pleural cavity.Methods The permeability and morphosis of the mesothelium of the parietal pleura in rat were investigated by intrapleura injection with tracers and observed by light microscopy and transmission electron.Results The mesothelial cells lining the parietal pleura appeared as both cuboidal and flattened cell bodies.The lymphatic capillaries were well developed in the submesothelial layer under the cuboidal cell regions.The results showed that in the cuboidal cell regions of the mesothelium of parietal pleura,tracers passed through mesothelial layers into lymphatics via the mesothelial stomata,the stomata was formed by the projections of lymphatic endothelial cell connecting with the prolongations of the cuboidal mesothelial cell.Conclusion The particulates directly enter the lymphatic capillaries of the parietal pleura from the pleural cavity through: ①The mesothelial stomata of the parietal pleura;②Phagocytized by the mesothelial cells;③Intercellular gaps of the mesotheliunm.