Histochemistry of acid phosphatase in small intestine mucosa in experimental coccidiosis in suckling piglets]

The activity of acid phosphatase (phosphohydrolase of orthophosphate monoesters; EC. 3.1.3.2) was evaluated densitometrically in the mucosa of duodenum, jejunum and ileum of 22 conventional piglets which were experimentally infected by oocysts of the coccidiae Isospora suis (infection dose of 200,000 oocysts) on day one after parturition (DAP). The activity of the studied hydrolase was investigated in the infected piglets during days two to ten after infection (DAI) in the intestinal mucosa (enterocytes) and in goblet cells. The density of the reaction product of acid phosphatase was simultaneously determined in the same mucosal cells of different sections of the small intestine in five control conventional piglets at the age of 2-14 days. In the small intestine mucosa of control piglets the activity of acid phosphatase was demonstrated to be located especially in the supranuclear zone of enterocytes. As for goblet cells, the reaction product of acid phosphatase is distributed in all zones (supra-, para-, infranuclear zones); the lowest density of this enzyme was found in the infranuclear zone. The activity of acid phosphatase is also localized in intestinal crypts: in their cells the enzyme concentration is decreasing from duodenum to caudal sections. Important changes were revealed, in comparison with the control data, in the development of the activity of acid phosphatase in the intestinal mucosa cells in the experimentally infected piglets. In the period of investigation (DAI 2-10) there were two stages of the development of the density of the enzyme reaction product. The first stage can be characterized by an increase, the other by a decrease in the level of acid phosphatase activity. Enterocytes are influenced in both stages, but the decrease in the density of the reaction product of acid phosphatase was observed only in absorption cells, and not in goblet cells. The increase in the activity of acid phosphatase occurs in the periods of DAI 4 and 9-10. Enzymatic deviations occur mainly in the absorption cells of the mucosa of duodenum and middle jejunum; in the cells of posterior jejunum and ileum an increase in the density of the reaction product of acid phosphatase was also demonstrated, but at the lower quantitative level (especially on DAI 4). The decrease in the activity of acid phosphatase has a protracted development and it takes place on DAI 5 to 8.(ABSTRACT TRUNCATED AT 400 WORDS)