Physiological and Serological Studies of Paragonimus miyazakii Infection in Rats

Abstract

In order to clarify the host responses in Paragonimus infection, paper-electrophoresis, determination of serum transaminase activities and agar double diffusion analysis were performed on serum from normal rats and those infected orally with Paragonimus miyazakii during the course of experimental infection. Between the 20th and 50th days of infection, severe gross pathological changes were seen on the surface of the liver. Activity of serum glutamic-pyruvic transaminase attained its peak on day 30, and that of serum glutamic-oxalacetic transaminase elevated gradually without apparent reduction throughout this experiment. Albumin was reduced from the 20th to the 30th day of infection, and the betaand gamma-globulins increased in the same period. Agar double diffusion analysis demonstrated an increase of antibody systems in sera from rats during the course of Paragonimus infection. However, in the late stage, from the 90th to the 150th days, the number of precipitin bands was reduced. Immunological study of host responses in parasitic infection may be an important approach to the elucidation of host-parasite relationships. In animals infected experimentally with several species of Paragonimus, Tomita (1956), So (1959), Kruidenier and Katoh (1959), Yogore et al. (1965) and others have reported results of immunological studies from different points of view and techniques. Liver damage, serum changes, and antibody production were studied by the above mentioned