Time-dependent alterations in serum NO concentration after oral administration of L-arginine, L-NAME, and allopurinol in intestinal ischemia/reperfusion.
OBJECTIVE
To study the effect of oral administration of a nitric oxide (NO) donor L-arginine (L-Arg), a NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) and an inhibitor of xanthine oxidase, allopurinol (Allo), on serum NO concentration and catalase activity after intestinal ischemia/reperfusion (I/R) in rats.


METHODS
Male Wistar rats receivedper os L-Arg (800 mg/kg) or L-NAME (50 mg/kg) or Allo (100 mg/kg) 24 hrs, 12 hrs and 1 hr before underwent 1 hr occlusion of superior mesenteric artery followed by 1 hr of reperfusion (L-Arg(IR1), L-NAME(IR1) and Allo(IR1) respectively) or 1 hr occlusion followed by 8 hrs of reperfusion (L-Arg(IR8), L-NAME(IR8) and Allo(IR8) respectively). There was one group underwent 1 hr occlusion (I), a group underwent 1 hr occlusion followed by 1 hr reperfusion (IR1), a group subjected to 1 hr occlusion followed by 8 hrs of reperfusion (IR8) and a last group that served as control (C). Serum NO concentration and catalase activity were measured.


RESULTS
After 1 hr of reperfusion serum NO concentration was elevated in IR1 and L-Arg(IR1) groups compared with group C but not in L-NAME(IR1) and Allo(IR1) group. Catalase activity was enhanced in L-NAME(IR1) group. Interestingly, serum NO concentration was increased after 8 hrs of reperfusion in all groups (IR8, L-Arg(IR8), L-NAME(IR8) and Allo(IR8)) compared with control while catalase activity did not show significant difference in any group.


CONCLUSIONS
The results of the present study show that NO concentration is elevated in serum after intestinal I/R and the elevation sustained after administration of L-Arg but not after administration of L-NAME or Allo after 1 hr reperfusion. However, after 8 hrs of reperfusion NO concentration was increased in all groups studied, focusing attention on its possible important role in a complicated situation such as intestinal I/R that involves intestine and other organs. Serum catalase activity does not seem to be affected by per os supplementation of L-Arg or Allo in intestinal I/R.
Department of Science of Dietetics and Nutrition, Harokopio University of Athens,Athens, Greece. ayanni@hua.gr
Amalia E
AE
Yanni
Eleutherios
E
Margaritis
Nikolaos
N
Liarakos
Alkisti
A
Pantopoulou
Maria
M
Poulakou
Maria
M
Kostakis
Despoina
D
Perrea
Alkis
A
Kostakis
D000284:Administration, Oral; D000493:Allopurinol / Q000008:administration & dosage*; D000818:Animals; D001120:Arginine / Q000008:administration & dosage*; D002374:Catalase / Q000097:blood; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000008:administration & dosage*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000098:blood supply / Q000187:drug effects*; D008297:Male; D017538:Mesenteric Artery, Superior; D008641:Mesenteric Vascular Occlusion / Q000150:complications* / Q000201:enzymology / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage*; D009569:Nitric Oxide / Q000097:blood*; D020030:Nitric Oxide Donors / Q000008:administration & dosage*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000201:enzymology / Q000209:etiology / Q000378:metabolism*; D013997:Time Factors; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors / Q000378:metabolism
D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D000493:Allopurinol; D001120:Arginine; D002374:Catalase; D019001:Nitric Oxide Synthase; D014969:Xanthine Oxidase; D019331:NG-Nitroarginine Methyl Ester