title: [Study on hepatocyte apoptosis of domestic pigs experimentally infected with Taenia asiatica and Taenia saginata].
abstract: OBJECTIVE
  To investigate apoptosis in liver tissue of the domestic pigs infected with eggs of Taenia asiatica and Taenia saginata.
  
  
  METHODS
  The adult worms of T. asiatica and T. saginata were collected and identified from the taeniasis patients in Dunyun and Congjiang districts, Guizhou province. Eggs were collected from gravid proglottids and prepared by washing and centrifugation. Nineteen 20-day hybrid domestic pigs (Duroc-Yorkshire-Landrace strain) were randomly divided into T. asiatica group (6 pigs), T. saginata group (8 pigs) and control group (5 pigs). Each animal of experimental groups was infected with 1.5 x 10(5) eggs by stomach injection. On day 15, 32, 46 and 74 after infection, animals were sacrificed and liver samples were collected for further experiments. The liver tissues were sliced for glass slides and prepared for ultrathin sections. The apoptosis of hepatocytes was identified by terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling. The morphological features of liver tissue were observed under transmission electron microscope.
  
  
  RESULTS
  The infection rate of two experiment groups reached 100%. Better developed cysticerci were found in liver of T. asiatica group than that of T. saginata group, but the liver pathological changes caused by cysticerci were similar. On day 15 and 32 after infection, hydropic degeneration, obvious vacuolization and some balloon-like degeneration were found in hepatocytes, and focal hepatic necrosis was observed. On day 46, spotty necrosis occurred in some local liver tissues. On day 74, main damages were granulomatous reactions surrounding cysticercus and focal liver fibrosis. On day 46, apoptosis index in T. asiatica group [(15.07 +/- 3.42)6%] and T. saginata group [(17.13 +/- 1.62)5%] was considerably higher than that in the control [(9.53 +/- 1.06)%] (P < 0.05). On day 74, apoptosis index in T. asiatica group [(27.33 +/- 0.92)5%] and T. saginata group [(34.20 +/- 0.73)%] was higher than that in the control [(13.60 +/- 2.26)%] (P < 0.05), and the apoptosis index in T. saginata group was significantly higher than that of T. asiatica group (P < 0.05). Simultaneously, morphological characteristics of apoptosis were clearly observed in hepatocytes in two experimental groups, showing shrunken, wrinkled and deformed nucleus with consolidation of chromosomes and appearance of apoptotic body.
  
  
  CONCLUSIONS
  The hepatocyte apoptosis of domestic pig is induced in the middle and late stages of infection by the cysticerci of T. asiatica and T. saginata, indicating that hepatic apoptosis might be related to focal liver fibrosis of the host caused by the cysticerci.
authors.affiliation: Department of Parasitology, Guiyang Medical College, Guiyang 550004, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Mou
authors.forename: Huai-En
authors.initials: HE
authors.lastname: Bao
authors.forename: Ke
authors.initials: K
authors.lastname: Zhang
authors.forename: Jia-Hong
authors.initials: JH
authors.lastname: Wu
authors.forename: Shu-Yuan
authors.initials: SY
authors.lastname: Lang
mesh_terms: D000818:Animals; D017209:Apoptosis; D005260:Female; D022781:Hepatocytes / Q000166:cytology*; D008099:Liver / Q000469:parasitology*; D008297:Male; D034421:Sus scrofa / Q000469:parasitology; D013552:Swine / Q000469:parasitology; D013553:Swine Diseases / Q000469:parasitology* / Q000473:pathology; D041202:Taenia saginata; D013622:Taeniasis / Q000473:pathology / Q000662:veterinary*