This study was undertaken to investigate the effect of praziquantel cn the Clonorchis sinensis, cn the parenchyma of the rabbits´ liver, and on the process of resolution of the injured parenchyma and bile ducts after disappearance of the fluke from the liver.
Each rabbit was infected with about 300 metacercariae of Clonorchis sinensis and was treated with usual or large (3 fold than normal) dosage of praziquantel.
Stool examinations for E.P.G. were done for 3 days before treatment and for the first 10 days every day and then on the 15th, 30th, and 60th day after treatment.
Macroscopic and microscopic histopathological examinations of the liver were done the 7th, 21th, 35th, and 49th day after infection and then on the 3rd, 15th, 30th, and 60th day after treatment.
Especially the ratio between the short diameter of bile ducts and the neighboring branch of the hepatic artery (B/A ratio) and the height of the epithelium of bile ducts were measured to testify the presence of the correlationship between the B/A ratio, the change of the height of the epithelium and histopathological findings.
The results are summarized as follows;
1. Almost of all the rabbits were infected heavily with Clonorchis sinensis (average E. P. G.;40, 250). The rabbits infected with Clonorchis sinensis were treated with usual or large dosage of the praziquantel. The E.P.G. on the first day after treatment was increased slightly than the aver age E.P.G. before treatment but thereafter decreased rapidly below 200 by 10-15 days after treatment and the F. P. G. of all cases of total 39 rabbits became negative within 30 days after
treatment. The efficacy of the praziquantel was very good in regard to above results.
2. There was no evidence of special hepatotoxic change on the histopathological examination of the rabbits´ liver infected with Clcncrchis sinensis between the group of usual dosage, high dosage and that of infection control.
3. The ratios between the short diameter of bile ducts, and that of the branch of hepatic artery on the point of lcm and 2cm centrifugal from the periphery of the right lobe of liver were increased to 4.6 and 8.8 times on the 49th day after treatment, and then decreased to 1.7 and 2.9 times on the 60th day after treatment than those of the non-infection control.
4. The height of the mucosal epithelium of bile ducts was increased rapidly until the 35th day after infection, and then slightly decreased very slowly after treatment.
5. The B/A ratio and the change of the height of the mucosal epithelium were seemed to be parallel to the histopathological alterations of the liver infected with Clonorchis sinensis.
|