Efeitos da dexametasona e pentoxifilina na esquistossomose mansoni experimental: aspectos do parasitismo e histopatologia hepática em camundongos da linhagem AKR/J

Abstract

The effects of the treatment of inbred AKR/J strain of mice by dexamethasone (DEX) or pentoxifylline (PTX) during acute and chronic phases of Schistosoma mansoni (LE strain) infection were evaluated. The administration of the drugs, probably by interfering with the immune response of the host, led to alterations in host-parasite relationship that resulted in changes on the pattern of development and fecundity of the worms and also on the characteristics of the hepatic granulomas, including the fibrous content and the apoptosis rate of cells making up the granulomatous lesions. Parasites recovered from the peritoneal cavity and portal system of rodents treated by DEX or PTX, in acute or chronic infection, showed higher means of the total length. Furthermore, sexual development and fecundity of the trematode were more evident in mice that received the glucocorticoid. In these animals it was verified an increasing in the number of eggs in the intestine and the presence of mature eggs of the parasite without cellular adhesion in the peritoneal cavity. No difference, nevertheless, in the total number of worms recovered from mice treated by both drugs was verified. The liver histopathology of mice subjected to treatment by DEX or PTX showed a reduction of inflammatory infiltrate, size of granulomas and fibrosis. The administration of DEX was related to a higher apoptosis rate among the cells of the granulomatous lesion, including lymphocytes, and a clear involvement, only during the acute phase, on the hepatic parenchyma of rodents. Additionally, new informations on the biology of S. mansoni in mice of the AKR/J strain were obtained