[Cytochemical study of the cysts of the sarcosporidian Sarcocystis bovicanis. I. Nucleic acids, polysaccharides, lipids and proteins].

A light microscopic study of S. bovicanis cysts and cyst stages has been carried out, in addition to morphological characterization of cysts. At least two types of cyst stages could be distinguished--merozoites and metrocytes. The light microscopic differentiation of the third type--the intermediate cells--from merozoites seems to be rather difficult especially when non-dividing cells are examined. Merozoites (zoites) much varied in size, and besides the usual parasitic cells with the terminal nuclei, cells with the central ones were recognized. Since the classical Feulgen reaction did not give sufficient results when establishing DNA distribution, its modification with a fluorescent agent Auramin O was used. The latter provided excellent results showing numerous chromatin granules in the nucleus, no distinct nucleoli being determined. Gallocyanin--chromalum method and methyl green--pyronin staining for DNA and RNA demonstrated a poor staining of the nucleus contrasting with an intensive coloration of cytoplasmic RNA and associated high level protein synthesis. The PAS reaction revealed numerous polysaccharide granules in the cytoplasm of zoites. On cryostat sections a certain PAS positive layer was distinguished around the cyst in the muscle tissue which did not disappear even after a long term amylase treatment. Even more intensively stained was the pre-cystic muscle after cytochemical test for general protein using amido black and coomassie blue. It does not seem unlikely that some metabolic changes may occur in the host cell harbouring the cyst. Several methods for lipid detection in cyst stages with Fat red, Oil red O and Sudan black B were used with negative results.(ABSTRACT TRUNCATED AT 250 WORDS)