The expulsion of Echinostoma trivolvis: worm kinetics and intestinal reactions in C3H/HeN mice treated with dexamethasone.
C3H/HeN mice were each infected with 40 Echinostoma trivolvis metacercarial cysts on day 0, given intramuscular injections of dexamethasone (DEX) daily for 30 days, and necropsied on days 5, 8, 12, 15, 20 and 30 p. i. Control mice were each infected with 40 echinostome cysts on day 0, but were not treated with DEX and necropsied on the same days as the DEX-treated mice. DEX treatment caused an inhibition of worm expulsion and suppressed the increase in goblet cell numbers that peaked around day 12 p. i. in the untreated control mice. Increase in the number of mucosal mast cells and eosinophils in the control mice that peaked around day 15 and 12 p. i., respectively, was also suppressed by the DEX treatment. The mean body area of the worms from the DEX-treated mice was about the same as that of the control worms on day 5 p. i., and then significantly greater than the control worms on days 8 and 12 p. i. The worms in the treated mice continued to grow until the end of the experiment, on day 30 p. i. Enzyme-linked immunosorbent assay (ELISA) showed that serum IgM from the treated and control mice increased from day 12 p. i., peaked on day 15 p. i., and then decreased. An IgM titre of the treated mice was slightly higher than that of the controls. No marked rise in IgG and IgA titres occurred throughout the experiment in both groups.
Fujino
T
T
Department of Biology, Faculty of Science, Yamagata University, Yamagata 990, Japan.
Ichikawa
H
H
Fried
B
B
Fukuda
K
K
D000818:Animals; D002452:Cell Count; D003907:Dexamethasone / Q000494:pharmacology*; D004449:Echinostoma; D004451:Echinostomiasis / Q000276:immunology*; D004804:Eosinophils / Q000473:pathology; D005938:Glucocorticoids / Q000494:pharmacology*; D006790:Host-Parasite Interactions / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000276:immunology; D007421:Intestine, Small / Q000187:drug effects / Q000276:immunology / Q000469:parasitology*; D008407:Mast Cells / Q000473:pathology; D051379:Mice; D008809:Mice, Inbred C3H
D005938:Glucocorticoids; D003907:Dexamethasone