BALB/c mice were used and divided into 2 experimental groups; group 1, infected with a single dose of 50 Clonorchis metacercariae and group 2, challenged with 50 metacercariae at the 4th week after primary infection with the same dose of
metacercariae.
Normal mice were served as control. Three mice in each group were examined weekly for 10 weeks. Mice in groups 1 and 2 were sacrificed. Liver including gall bladder and common bile duct was extracted and worms were counted. On the other hand,
mice
in
group 1, group 2 and control group were intraperitoneally injected with ethanol and fixed. The liver including common bile duct and regional lymphnodes and the small intestine were fixed by 10% formalin solution, and sectioned serially and
stained
with
toluidine blue for examination of appearance degree of mast cells. The mesenterium was used for examination of appearance degree of mast cells and percentage of degranulating cells.
@ES The results obtained in this study are summarised as following:
@EN 1) Average number of worm recovered was 13.1 in group 1 and 15.7 in group 2, respectively, throughout the examination. Mean number by week after reinfection in group 2 reveled a slight increase, ranging from 3.0 to 9.0, comparing with those
in
group
1.
2) In control mast cells were found in the mesenterium, but not in the bile duct, small intestine and lymphnodes. No mast cells were found in the small intestine in groups 1 and 2. In group 1 mast cells showed a moderate appearance degree at the
3rd
week and persisted for 2-4 weeks in the bile duct, mesenterium and lymphnodes. Group 2 showed a moderate or marked degree which persisted for longer period after reinfection in the tissues.
3) Average percentage of degranulating cells in the mesenterium was 9.1% in control and 26.3% in group 1, respectively, throughout the examination and 51.7% during 6 weeks after reinfection in group 2. The peak was 36.7% at the 3rd week after
primary
infection in groups 1 and 2. In group 2, the percentage of degranulating cells increased promptly and markedly to 77.3% at the lst week after reinfection.
4) Chronological changes of appearance degree of mast cells and percentage of degranulating cells in the tissues, particularly in the bile duct showed an obvious tendency to parallel to chronological change of number of worm recovered in the
liver.
From the adove results, it is strongly suggested that mast cells in mice infected with Clonorchis sinensis are deeply implicated I expulsion of worms in bile duct.
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