Phospholipase B activity in congenitally athymic (nude) mice infected with Trichinella spiralis.

The effects of an infection with 200 Trichinella spiralis larvae on the intestinal phospholipase B activity and bone marrow eosinophilia of congenitally athymic (nude) mice (BALB/c; NU/NU) were studied. Nude mice were used since it had been shown that they do not undergo a typical worm expulsion and also they lack a thymus. The results showed that nude mice do not develop either an increased bone marrow eosinophilia or an elevation in intestinal phospholipase B activity. The findings thus support the hypothesis that phospholipase B is involved in the expulsion of parasitic worms and that elevated enzyme levels and expulsion are thymus cell dependent.