| Abstract: | In the small intestine of 16 gnotobiotic piglets infected a day post partum (DPP) by Isospora suis coccidia the activities were studied of selected dehydrogenases and monoaminoxidase (O2 oxidoreductase, MAOx, EC 1.4.3.4.). The following dehydrogenases were investigated: succinate dehydrogenase (SDH, EC 1.3.99.1.), glycerol-3-phosphate dehydrogenase (glycerol-3-phosphate:menadion oxidoreductase, GPOX, EC 1.1.99.5.) and tetrazolium oxidoreductase (NADH, ES 1.6.99.3.). The activities of NADH and GPOX were found to decrease, a decrease being somewhat milder in MAOx, at a high infection dose of I. suis oocysts (750,000 oocysts), in comparison with the control, already on the first day after infection (DAI). The SDH levels did not change. In piglets infected by a low infection dose of I. suis oocysts a double marked decrease (negative to slightly positive finding) was recorded in the period from the third to the eighth day after infection (DAI). A similar pattern with a longer time interval between the decreases was observed in GPOX (4th to 11th day after infection). The findings of SDH and MAOx activities were different. The SDH activity is maintained at the same level (++) for the whole period of investigation and there occurs a decrease (+) only on the 9th day after infection, persisting until 11 DAI. The MAOx activity and its change correspond to the SDH activity; the difference being that in the second group the starting level is high ( ) and on the eleventh day after infection it is low or medium (0-++), in comparison with the standard. This variability is discernible from 8th DAI. |
