title: Effects of oral administration of (L)-arginine, (L)-NAME and allopurinol on intestinal ischemia/reperfusion injury in rats.
abstract: OBJECTIVE
  Intestinal ischemia/reperfusion (I/R) injury is implicated in many clinical conditions, and it performs a fundamental role in their pathophysiologies. Oral administration of antioxidants and nitric oxide (NO) donors ameliorate intestinal injury. Here, the effects of l-arginine, allopurinol and N(G)-nitro-l-arginine methyl ester (l-NAME) were investigated.
  
  
  METHODS
  One hundred twenty-eight male Wistar rats were separated into 4 groups and subjected to occlusion of the superior mesenteric artery for 60 min. The Control group did not receive any substance before the surgical operation. However, the 3 other groups received the following: l-arginine (800 mg/kg body weight; l-Arg group), l-NAME (50mg/kg; l-NAME group) or allopurinol (100mg/kg; Allo group). Each substance was given by mouth in 3 equal doses 24, 12 and 1h before the surgical operation. Each group was then divided into 4 subgroups, which underwent different durations of reperfusion (0, 1, 8 or 24h). At the end of each time point, blood and tissue samples were collected, and histological examinations were performed. Serum nitrite and catalase, intestinal tissue myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) levels were determined.
  
  
  RESULTS
  At each reperfusion time point, the Allo group exhibited the mildest histological lesions in contrast to the l-NAME group, which showed the most severe lesions. MPO was decreased significantly in the Allo and l-Arg groups during reperfusion, and allopurinol administration caused earlier and stronger effect. iNOS and NT levels were higher in the l-Arg group and lower in the Allo group. Serum nitrite and catalase were increased in the l-NAME group after 24h.
  
  
  CONCLUSIONS
  Oral administration of allopurinol exerted a strong and protective effect on the intestinal tissue that was subjected to I/R earlier than l-arginine. This finding was also supported with the MPO, iNOS and NT data.
authors.affiliation: Laboratory of Experimental Surgery and Surgery Research "N. Christeas", Medical School, National and Kapodistrian University of Athens, Greece.
authors.forename: Eleftherios V
authors.initials: EV
authors.lastname: Margaritis
authors.forename: Amalia E
authors.initials: AE
authors.lastname: Yanni
authors.forename: George
authors.initials: G
authors.lastname: Agrogiannis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Liarakos
authors.forename: Alkisti
authors.initials: A
authors.lastname: Pantopoulou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Vlachos
authors.forename: Antonios
authors.initials: A
authors.lastname: Papachristodoulou
authors.forename: Pinelopi
authors.initials: P
authors.lastname: Korkolopoulou
authors.forename: Efstratios
authors.initials: E
authors.lastname: Patsouris
authors.forename: Maria
authors.initials: M
authors.lastname: Kostakis
authors.forename: Despina N
authors.initials: DN
authors.lastname: Perrea
authors.forename: Alkiviadis
authors.initials: A
authors.lastname: Kostakis
mesh_terms: D000284:Administration, Oral; D000493:Allopurinol / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology*; D002374:Catalase / Q000097:blood / Q000187:drug effects; D007422:Intestines / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage / Q000494:pharmacology*; D052247:Nitric Oxide Synthase Type II / Q000187:drug effects / Q000378:metabolism; D009573:Nitrites / Q000097:blood; D009195:Peroxidase / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000503:physiopathology*; D013997:Time Factors; D014443:Tyrosine / Q000031:analogs & derivatives / Q000187:drug effects / Q000378:metabolism
chemical_list: D009573:Nitrites; C002744:3-nitrotyrosine; D014443:Tyrosine; D000493:Allopurinol; D001120:Arginine; D002374:Catalase; D009195:Peroxidase; D052247:Nitric Oxide Synthase Type II; D019331:NG-Nitroarginine Methyl Ester