Cell Types in the Normal Pleural Fluid from Rabbits

Our knowledge of the cell types from normal pleural fluid of laboratory animals forms the basis of our experimental investigation of the inflammatory diseases of the pleura in humans. We sought to standardise the various cell numbers in normal pleural fluid of rabbits as well as assess the use and power of aspiration and pleural lavage as experimental tools. Fluid from the left and right pleural spaces was aspirated from three of six white rabbits, while the remaining three produced irrigated fluid. Cell types seen in prepared smears from these procedures comprised the following: monocytes, lymphocytes, macrophages, mesothelial cells (intact and degenerative), polymorphonuclear leukocytes and others that could not be identified definitively. The only significant difference between pleural lavage and aspiration was in the number of mesothelial cells obtained from both procedures. The similarity in different cell counts obtained in the rabbit and human pleural fluids thus makes the rabbit a useful model for investigating inflammatory diseases of the pleura in humans. Lavage and aspiration were useful tools in these experiments.