[Cellular interactions in the intracellular parasitism of cryptosporidia. I. The effect of Cryptosporidium parvum on the phosphatase activity in the small intestine enterocytes of experimentally infected newborn rat pups].

Cytochemical methods for detection of non-specific phosphatases were employed at the light microscope level for identification of enzymatic activity in the small intestine of new-born rats (6--11 days old), both infected and non-infected with the intestinal coccidium Cryptosporidium parvum. In the new-born rats, the level of alkaline and especially acid phosphatase is originally very low, suggesting their insignificant involvement in digestion processes in suckling animals compared to rats of older age (3 month old). However, a heavy colonization of the brush border of the intestinal villi of the new-born rats with cryptosporidia results in obvious inactivation of phosphatases in the infected enterocytes, in contrast to the neighbouring parasite-free host cells. The general picture of metabolic interaction between cells of a unicellular parasite (C. parvum) and those of its metazoan host (rat) much resembles that observed in the course of Elmeria spp. infection, but differs from that induced by Toxoplasma gondii endogenous stages in the cat intestine. Details of cell interaction with intracellular parasitism need additional studies at the ultrastructural level.