Changes in the activity and kinetics of mouse intestinal glutathione transferase during experimental trichinellosis

The glutathione S-transferases (GSTs) are a group of multifunctional enzymes, which play a critical role in cellular detoxification. Our investigations deal with the contribution of GST in the biochemical defense against Trichinella spiralis infection. The aim of this study was to examine the effect of T. spiralis infection on the total activity and kinetic properties of cytosolic GST in the intestine during the intestinal phase of experimental trichinellosis in mice. Our results showed a statistically significant increase (relative to the uninfected control) in the total GST activity both in the small and large intestines of the infected mice. Moreover, we observed changes in the kinetics of substrate saturation of GST. Trichinellosis in the small intestine caused a 12-fold decrease in the low K m value and a sixfold increase in the high K m value. In the large intestine, infection with T. spiralis caused only a fivefold increase in the low K m value, whereas the high K m value remained unchanged. We suggest that GST from the mouse small intestine could be involved in the detoxification of parasite excretory–secretory products released to the host intestine during trichinellosis and that these products influence the quaternary structure of this enzyme.