Development of an animal model of hepatic fibrosis by excretory-secretory antigen of Ascaris suum.

ABSTRACT

OBJECTIVE: The excretory-secretory (ES) antigens of Ascaris suum are known to cause hepatic damage in animals. The present study was aimed at developing an animal model of hepatic fibrosis with these antigens. METHODS: Three doses of ES antigens of A. suum were injected into 24 golden hamsters on days 0, 10 and 20. Batches of 8 animals each were sacrificed at 3 days, 45 days and 90 days after the third injection, after collection of blood. Three groups of 6 control animals each were injected with normal saline and were sacrificed similarly. Liver biochemistry, leukocyte migration inhibition test on cells separated from spleen, and liver histology were carried out. RESULTS: Serum ALT levels in experimental animals were significantly higher than those in control animals at days 3, 45 and 90 after the last antigen dose; AST levels were elevated 45 and 90 days after the last dose of ES antigen. Leukocyte migration inhibition in experimental animals was 58.2 (8.5)%, 51.6 (11.2)% and 50.5 (12.8)% at days 3, 45 and 90 after the last antigen dose. Marked centrivenular degeneration and necrosis were observed in liver tissue in all the experimental animals sacrificed 72 h after the last antigen dose. Condensation of reticulin around the portal zone with extension into the liver lobule was observed in 4 of 8 and 7 of 8 experimental animals sacrificed 45 and 90 days, respectively, after the last dose. Control animals did not have such lesions. CONCLUSION: An animal model of hepatic fibrosis could be produced by repeated injection of ES antigens of A. suum.