| Home | E-Submission | Sitemap | Contact us |  
Korean J Parasitol > Volume 23(1):1985 > Article

Original Article
Korean J Parasitol. 1985 Jun;23(1):47-57. English.
Published online Mar 20, 1994.  http://dx.doi.org/10.3347/kjp.1985.23.1.47
Copyright © 1985 by The Korean Society for Parasitology
Studies on intestinal trematodes in Korea XIX. Light and scanning electron microscopy of Fibricola seoulensis collected from albino rats treated with praziquantel
Byong Seol Seo,In June Cha,Jong Yil Chai,Sung Jong Hong and Soon Hyung Lee
Department of Parasitology and Institute of Endemic Deseases, College of Medicine, Seoul National University, Seoul 110, Korea.

An experimental study was performed to observe the in vivo effects of praziquantel on the light and scanning electron microscopic morphology of Fibricola seoulensis. The metacercariae were obtained from the snakes and 1,000 in each number was orally given to total 15 albino rats; 5 controls and 10 treatment group. Seven days later the 10 rats were treated with 10 mg/kg praziquantel and sacrificed 1-24 hours later to search for the worms from their small intestines. The major light microscopic changes in the drug-exposed worms were early contraction followed by relaxation of especially their forebody, vacuolization of the tegument and subtegumental parechymal layers, and narrowing of the intestinal lumens. The scanning electron microscopic findings were characterized by formation of numerous blebs followed by rupture and subsequent destruction of their whole tegument. These results show that the change in worm body is not confined to the tegument but extends to deeper parechymal portions and also occurs in their intestines. It is suggested that the drug uptake by the worms should be either through their tegument or through the digestive tract.


Fig. 1
Changes in size of F. seoulensis after exposure to praziquantel in vivo.

Figs. 2-5
Fig. 2. A normal adult worm of F. seoulensis showing its characteristic feature. Acetocarmine stain (scale: 0.1mm).

Fig. 3. Two drug-exposed specimens (6-hour group). The forebody is contracted while the hindbody elongated.The lateral margins show hazy appearance (arrow heads) due to severe vacuolizations. Acetocarmine stain (scale: 0.2mm).

Fig. 4. The laateral margin of a worm (24-hour group). The tegument is markedly destroyed and many vacuoles are seen in the superficial and deep layers (scale: 0.1mm).

Fig. 5. Another worm (24-hour group) showing many parenchymal vacuoles (scale: 25µm).

Figs. 6-9
Fig. 6. A sectioned worm of 6-hour group. The lateral margins of the forebody show many vacuoles (arrow heads). H-E stain (scale: 0.1mm).

Fig. 7.Ibid, 24-hour group. The vacuolization of the parenchymal tissues is conspicuous. H-E stain (scale: 25µm).

Fig. 8. Cross section of a control worm showing two intact intestines (arrow heads) with wide lumens and thin walls. H-E stain (scale: 25µm).

Fig. 9. Section of the drug-exposed worms (a: 6-hour group, b: 24-hour group) showing their nearly occluded intestinal lumen and thickened wall. H-E stain (scale: 25µm).

Figs. 10-13
Fig. 10. Scanning electron microscopic view of the lateral margin of a drug-exposed worm (1-hour group).Many tegumental blebs are seen (arrow heads) and the tegumental architecture is severely altered (scale: 35µm).

Fig. 11. Magnification of an arrow portion of Fig. 10. The tegumental blebs are much variable in size and shape (scale: 4µm).

Fig. 12. The tegumental surface of the hindbody of a not severely damaged worm (6-hour group). Many blebs are seen and the cobblestone-like tegumental integrity is a little deformed (scale: 2.5µm).

Fig. 13. The tegument around oral sucker of a drug-exposed worm (1-hour group). The ruptured blebs (arrow heads) are seen but the spines are entirely intact (scale: 4µm).

Figs. 14-17
Fig. 14. Another worm in the same group as Fig. 13, showing the tegument between oral and ventral suckers. Despite the bleb formation (large arrows) on the tegument, the sensory papillae appear to be intact (small arrow heads). The blebs and the sensory papillae grossly have no relations each other (scale: 5µm).

Fig. 15. The forebody of a drug-exposed dead worm (6-hour group) recovered from the caecum of a rat. The whole tegumental surface is severely destroyed (scale:33µm).

Fig. 16. Magnification of the worm in Fig. 15. There is no recognizable tegumental structures such as the spines, sensory papillae, etc. (scale: 4µm).

Fig. 17.Ibid, another portion. The tegumental surface shows much rough and dirty appearance (scale 4µm).

1. Andrews P, Thomas H, Pohlke R, Seubert J. Praziquantel. Med Res Rev 1983;3(2):147–200.
2. Becker B, Mehlhorn H, Andrews P, Thomas H. Scanning and transmission electron microscope studies on the efficacy of praziquantel on Hymenolepis nana (Cestoda) in vitro. Z Parasitenkd 1980;61(2):121–133.
3. Becker B, Mehlhorn H, Andrews P, Thomas H, Eckert J. Light and electron microscopic studies on the effect of praziquantel on Schistosoma mansoni, Dicrocoelium dendriticum, and Fasciola hepatica (Trematoda) in vitro. Z Parasitenkd 1980;63(2):113–128.
4. Chiu HS, et al. Korea Univ Med J 1982;19(3):617–630.
5. Hong ST, Cho TK, Hong SJ, Chai JY, Lee SH, Seo BS. Fifteen human cases of Fibricola seoulensis infection in Korea. Korean J Parasitol 1984;22(1):61–65.
6. Kim SS, et al. Korea Univ Med J 1982;19(1):91–105.
7. Lee SH. Seoul J Med 1985;26(1):41–52.
8. Lee SH, Chai JY, Seo BS. Studies on intestinal trematodes in Korea: XVIII. Effects of praziquantel in the treatment of Fibricola seoulensis infection in albino rats. Korean J Parasitol 1985;23(1):41–46.
9. Mehlhorn H, Becker B, Andrews P, Thomas H, Frenkel JK. In vivo and in vitro experiments on the effects of praziquantel on Schistosoma mansoni. A light and electron microscopic study. Arzneimittelforschung 1981;31(3a):544–554.
10. Mehlhorn H, Kojima S, Rim HJ, Ruenwongsa P, Andrews P, Thomas H, Bunnag B. Ultrastructural investigations on the effects of praziquantel on human trematodes from Asia: Clonorchis sinensis, Metagonimus yokogawai, Opisthorchis viverrini, Paragonimus westermani and Schistosoma japonicum. Arzneimittelforschung 1983;33(1):91–98.
11. Pax R, Bennett JL, Fetterer R. A benzodiazepine derivative and praziquantel: effects on musculature of Schistosoma mansoni and Schistosoma japonicum. Naunyn Schmiedebergs Arch Pharmacol 1978;304(3):309–315.
12. Ruenwongsa P, et al. Life Sci 1983;32:25–29.
13. Seo BS, Lee SH, Chai JY, Hong ST, Hong SJ. [Studies on intestinal trematodes in Korea X. Scanning electron microscopic observation on the tegument of Fibricola seoulensis]. Korean J Parasitol 1984;22(1):21–29.
14. Seo BS, Lee SH, Hong ST, Hong SJ, Kim CY, Lee HY. Studies On Intestinal Trematodes In Korea: V. A Human Case Infected By Fibricola Seoulensis (Trematoda: Diplostomatidae). Korean J Parasitol 1982;20(2):93–99.
15. Seo BS, Rim HJ, Lee CW. Studies on the parasitic helmiths of Korea: I. Trematodes of rodents. Korean J Parasitol 1964;2(1):20–26.
16. Sirisinha S, Puengtomwatanakul S, Sobhon P, Saitongdee P, Wongpayabal P, Mitranonde V, Radomyos P, Bunnag D, Harinasuta T. Alterations of the surface tegument of Opisthorchis viverrini exposed to praziquantel in vitro and in vivo. Southeast Asian J Trop Med Public Health 1984;15(1):95–103.
17. Xiao SH, Friedman PA, Catto BA, Webster LT Jr. Praziquantel-induced vesicle formation in the tegument of male Schistosoma mansoni is calcium dependent. J Parasitol 1984;70(1):177–179.
Editorial Office
c/o Department of Medical Environmental Biology
Chung-AngUniversity College of Medicine, Dongjak-gu, Seoul 06974, Korea
Tel: +82-2-820-5683   Fax: +82-2-826-1123   E-mail: kjp.editor@gmail.com
About |  Browse Articles |  Current Issue |  For Authors and Reviewers
Copyright © 2019 by The Korean Society for Parasitology and Tropical Medicine. All rights reserved.     powerd by m2community