Morphological observations on <i>Clonorchis sinensis</i> obtained from rats treated with praziquantel

, Rim, Han Jong; , Park, Hee Young; , Kim, Soo Jin; , Lee, Sook Hee

doi:1980.18.2.192

Korean J Parasito > Volume 18(2):1980 > Article

Original Article


Korean J Parasitol. 1980 Dec;18(2):192-198. English. Published online Mar 20, 1994. http://dx.doi.org/10.3347/kjp.1980.18.2.192
Copyright © 1980 by The Korean Society for Parasitology


Morphological observations on Clonorchis sinensis obtained from rats treated with praziquantel
Han-Jong Rim,Hee-Young Park,Soo-Jin Kim and Sook-Hee Lee
Department of Parasitology and Institute for Tropical Endemic Diseases, College of Medicine, Korea University, Korea.


Abstract
The present study was undertaken to observe the morphological changes of Clonorchis sinensis obtained from experimentally infected rats treated with praziquantel (Biltricide®) which is a new anthelmintic agent with high activity against a broad spectrum of cestode and trematode species. For this study, the rats were infected experimentally with about 50 metacercariae of C. sinensis and were given praziquantel a single dose of 600 mg per kg of body weight at 5 weeks after infection. The Clonorchis worms were isolated from the bile ducts of the rats which were autopsied on the 4th day after treatment. After isolation the parasites were observed their shape and motility in the medium of 37℃ physiological saline solution, and then the fine structure of the tegument of C. sinensis was studied by means of light, scanning and transmission electron microscope. The findings of the observation were compared with those of untreated parasites. The results are as follows: 1. All the isolated worms moved actively in the medium of physiological saline solution (37℃). A majority of the parasites obtained from the treated rats showed a large balloon shaped structure on the surface between oral and ventral suckers. But such structure has never seen in the parasites obtained from control rats. 2. By the scanning electron microscopic observation, the regular pattern of the tegumental ridges was significantly changed on the outer surfaces of parasites obtained from the treated rats as compared with those of the control rats. 3. By the transmission electron microscopic observation, the numerous mitochondriae in the syncytial tegumental layer of the treated parasites appeared to be degenerated and formed small vacuoles, and the tegumental ridges were also degenerated and showed somewhat flattened. 4. In the parasites obtained from the treated rats, a different size of vacuoles interspersed in the distal part of the syncytial tegument and also in subepithelial region of the urinary bladder. These vacuoles are fused each other and lead to the disruption of the apical region of syncytial tegument along the basement layer. Finally the basement layer was dislocated. So that the tegumental layer appeared as a large balloon.

Figures


	Fig. 1 SEM (Scanning electron microscopy) of control C. sinensis. Showing anterior part of worm and oral sucker (Os) ×36.


	Fig. 2 SEM of treated C. sinensis. Showing balloon shaped structure (Ba) between oral (Os) and ventral suckers. ×72.


	Fig. 3 SEM of the surface of untreated worm. Showing regular pattern of tegumental ridges (TR). ×4,200.


	Fig. 4 SEM of the surface of treated worm. Showing degenerated tegumental ridges (TR). ×4,400.


	Fig. 5 TEM (Transmission electron microscopy) of the tegument of control worm. Showing the organization of syncytial tegument (STg) with tegumental ridges (TR), basement membrane (Bm), longitudinal musculature (LM) and mitochondria (Mi). ×15,000.


	Fig. 6 TEM of the tegument of treated worm. Showing degenerated mitochondria (Mi) in the syncytial tegument (STg). ×15,000.


	Fig. 7 TEM of the epithelial region of excretory bladder of treated worm. Showing many different size of vacuoles (V) and microtubules (Mt). ×10,000.


	Fig. 8 TEM of the surface of treated worm. Showing degenerated tegumental rideges (TR). ×10,000.

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