title: Hyperammonemia, brain edema and blood-brain barrier alterations in prehepatic portal hypertensive rats and paracetamol intoxication.
abstract: OBJECTIVE
  To study the blood-brain barrier integrity, brain edema, animal behavior and ammonia plasma levels in prehepatic portal hypertensive rats with and without acute liver intoxication.
  
  
  METHODS
  Adults male Wistar rats were divided into four groups. Group I: sham operation; II: Prehepatic portal hypertension, produced by partial portal vein ligation; III: Acetaminophen intoxication and IV: Prehepatic portal hypertension plus acetaminophen. Acetaminophen was administered to produce acute hepatic injury. Portal pressure, liver serum enzymes and ammonia plasma levels were determined. Brain cortex water content was registered and trypan blue was utilized to study blood brain barrier integrity. Reflexes and behavioral tests were recorded.
  
  
  RESULTS
  Portal hypertension was significantly elevated in groups II and IV. Liver enzymes and ammonia plasma levels were increased in groups II, III and IV. Prehepatic portal hypertension (group II), acetaminophen intoxication (group III) and both (group IV) had changes in the blood brain-barrier integrity (trypan blue) and hyperammonemia. Cortical edema was present in rats with acute hepatic injury in groups III and IV. Behavioral test (rota rod) was altered in group IV.
  
  
  CONCLUSIONS
  These results suggest the possibility of another pathway for cortical edema production because blood brain barrier was altered (vasogenic) and hyperammonemia was registered (cytotoxic). Group IV, with behavioral altered test, can be considered as a model for study at an early stage of portal-systemic encephalopathy.
authors.affiliation: Cátedra de Fisiopatología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
authors.forename: Camila
authors.initials: C
authors.lastname: Scorticati
authors.forename: Juan P
authors.initials: JP
authors.lastname: Prestifilippo
authors.forename: Francisco X
authors.initials: FX
authors.lastname: Eizayaga
authors.forename: José L
authors.initials: JL
authors.lastname: Castro
authors.forename: Salvador
authors.initials: S
authors.lastname: Romay
authors.forename: María A
authors.initials: MA
authors.lastname: Fernández
authors.forename: Abraham
authors.initials: A
authors.lastname: Lemberg
authors.forename: Juan C
authors.initials: JC
authors.lastname: Perazzo
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology*; D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001812:Blood-Brain Barrier / Q000502:physiology*; D001929:Brain Edema / Q000378:metabolism*; D006801:Humans; D022124:Hyperammonemia / Q000378:metabolism*; D006975:Hypertension, Portal / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen