[Histochemistry of selected peptidases in small intestine mucosa in piglets experimentally infected with Isospora suis].

In the small intestine mucosa of 24 gnotobiotical piglets experimentally infected the first day post partum with oocysts of the coccidium Isospora suis, the activities of dipeptidylpeptidase IV (EC.3.4.14.5.; DAP IV) and gamma-glutamyl transferase (EC.2.3.2.2.; GGT) in the microvillous zone of enterocytes were evaluated by scanning densitometry. The tissue of the small intestine in piglets infected with a dose of 100,000 oocysts of the coccidia of I. suis was examined in the period from the first till the eleventh day post infection (DPI). In the control piglets at the age of 2-5 days it was found that most of the DAP IV activity was located in the microvillous zone of the enterocytes of the middle jejunum, rear jejunum and ileum. The DAP IV activity of duodenum mucosa was lower; as compared with the activity in the mucosa of the jejunum and ileum it reached 53-57%. In the case of GGT activity, the highest density values of the reaction product were recorded in the microvillous zone of enterocytes of the duodenum and the whole jejunum, the lowest in the ileum mucosa (86-89%) of the activity found in the duodenum and jejunum). During the experimental infection the infected piglets had a significant deficit of both peptidases, especially DAP IV (the whole studied period). The development of GGT activity was slightly different with the onset of the marked decline of the enzyme activity only on the fifth DPI. The lower GGT activity persisted till the eighth DPI. The density of the GGT reaction product began to return to the normal on the ninth to eleventh DPI. No predisposition in the location of the deficit was observed in the peptidases studied during the infection. The decline of the activity of both enzymes influenced also the mucosa of all studied parts of the small intenstine. The difference lay in the relevance of lowering of the density of reaction product of DAP IV and GGT on other DPI and in the different intensities of the return of the activity to the physiological normal.