Period of Hyperbaric Oxygen Delivery Leads to Different Degrees of Hepatic Ischemia/Reperfusion Injury in Rats.
BACKGROUND
This study evaluated the morphology of the rat liver when hyperbaric oxygen (HBO) was used at various stages of ischemia and reperfusion.


METHODS
Thirty-two male Wistar rats, subjected to 30 minutes of hepatic ischemia and 30 minutes of reperfusion, were randomly assigned as follows: GIR (n = 8), control without HBO; GHBO/I (n = 8), in which HBO was applied only during ischemia; GHBO/R (n = 8), HBO only during reperfusion; and GHBO/IR (n = 8), HBO during both ischemia and reperfusion. Feasibility scores of hepatocytes were determined by assessing 8 items related to liver injury.


RESULTS
The histologic injury score of the hepatic specimens was significantly lower in the GHBO/I group (79.0 ± 0.1) compared with the GIR group (135.0 ± 0.1). HBO was not effective when applied during reperfusion (GHBO/R, 151.3 ± 0.1) or during the ischemia plus reperfusion period (GHBO/IR, 131.0 ± 0.1). The sum was significantly higher (P < .05) in HBO-treated animals during the reperfusion period (ie, in the GHBO/R group compared with any of the other groups).


CONCLUSIONS
A favorable effect was obtained when HBO was administered early during ischemia. HBO given in later periods of reperfusion was associated with a more severe sum index percentage of liver damage.
Medicine School, Federal University of Grande Dourados, Mato Grosso do Sul, Dourados-MS, Brazil.
J C
JC
Chaves
Medicine School, Federal University of Grande Dourados, Mato Grosso do Sul, Dourados-MS, Brazil.
F S
FS
Neto
Medicine School, Federal University of Grande Dourados, Mato Grosso do Sul, Dourados-MS, Brazil.
A T
AT
Ikejiri
Medicine School, Federal University of Grande Dourados, Mato Grosso do Sul, Dourados-MS, Brazil.
P R
PR
Bertoletto
Department of Surgery, Federal University do Mato Grosso do Sul, Mato Grosso do Sul-MS, Brazil.
R
R
Teruya
Department of Morphology and Genetic, Federal University of São Paulo (UNIFESP), São Paulo, Brazil.
R
R
Santos Simões
Marília Medical School, Marília-SP, Brazil.
E H
EH
Tikazawa
Marília Medical School, Marília-SP, Brazil.
J B
JB
Liu
Medical School of Anhembi Morumbi University, São Paulo-SP, Brazil.
F L
FL
Carrara
Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil.
M O
MO
Taha
Surgical Techniques and Experimental Surgery Division, Surgery Department, São Paulo Federal University-UNIFESP, São Paulo-SP, Brazil. Electronic address: djfagundes.dcir@epm.br.
D J
DJ
Fagundes
D000818:Animals; D004195:Disease Models, Animal; D006931:Hyperbaric Oxygenation / Q000379:methods*; D019194:Ischemic Preconditioning; D008099:Liver / Q000098:blood supply* / Q000473:pathology; D008107:Liver Diseases / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000628:therapy*
D010100:Oxygen