RESUMO
Prolonged stimulation of newborn mice by intraperitoneal injections with inactivated staphylococci induces a chronic neonatal inflammatory reaction and an associated oxidative-stress response. The chronically stimulated animals exhibit anorexy. show a reduction in their body weight and undergo a depression in both antibody synthesis andin vitro proliferativc response of Con A-stimulated splenic T-lymphocytes. These stressed animals also develop adrenal hyperplasia, hypozincamia and thymic hypoplasia. Despite this stress-mediated thymic involution, Con-A stimulated T-lymphocytes from thymus displayed increased theirin vitro proliferative response. Results of the present work show that intramuscular injections of zinc acetate in stressed mice, one single dose (5 microg) every other day for two weeks, reduce both the zinc concentration in the thymus gland and thein vitro proliferative response of their Con A-stimulated T-lymphocytes. The results suggest that prophylactic administration of zinc can have benefical consequences on the immunity of chronically stressed mice.
RESUMO
This article describes the enterobacterial common antigen (ECA) content in the liver and spleen extracts from immunosuppressed two months old CFW mice which received a single dose (400 mg/kg body weight) of cyclophosphamide (CY). A complement fixation inhibition assay was used to measure the tissular concentration of ECA. The results showed that liver and spleen ethanol-soluble extracts from immunosuppressed mice had a greater quantity of ECA than those obtained from healthy mice (p < 0.001). Previous works have proven that ECA is a hapten shared by almost all Gram-negative bacteria, and CY is an alkylating agent useful to induce bacterial translocation. Therefore, the increments observed in tissular ECA concentration may indicate the extension of the enterobacterial dissemination from intestine to abdominal organs in CY-treated immunosuppressed mice.