[Mononucleated phagocytes and mesothelial cells in serous peritoneal effusion fluid]

Twenty one peritoneal effusions from patients with cirrhosis were studied in order to characterize mesothelial cells, monocytes and their vacuolated forms. Morphological investigations were performed after Papanicolaou, M.G.G. and Giemsa stains; cytochemical studies by P.A.S., Alcian Blue pH 2,5 and Sudan Black B techniques. Seven enzymatic activities were appreciated: Naphtyl Acetate Esterase, Acid Phosphatase pH 5, beta Glucuronidase, Lactico-dehydrogénase, Malico D, NADH.D and Peroxidase pH 7,6. The free mesothelial cells show a metabolic and functional active phase in which their hydrolasic equipment suggests an intense lysosomal activity only correlated to pinocytosis. Monocytes in transudates show a morphologically micro-vacuolated macrophagic transformation of pinocytic type (elicited macrophages ?); they only become cytophagic when an acute inflammation occurs (activated macrophages ?). This paper emphasizes analogy of behaviour of mesothelial cells and monocytes in transudates, but demonstrates differences in their energetic metabolisms and endocytic characteristics.