Hyperbaric oxygen therapy protects the liver from apoptosis caused by ischemia-reperfusion injury in rats

: The present paper aimed to investigate the role of hyperbaric oxygen treatment (HBO) and the apoptosis in rat liver ischemia-reperfusion injury (IRI).

: Thirty-seven male Wistar rats were subjected to 30 minutes of hepatic ischemia and 30 minutes of reperfusion and randomly distributed into six groups: G-I/R (n = 8), control without HBO; G-HBO/I (n = 8), HBO only during the ischemia period; G-HBO/R (n = 8), HBO only during the reperfusion period; G-HBO-I/R (n = 8), HBO during both the ischemia and reperfusion periods; G-Sh (n = 3), HBO without ischemia or reperfusion as sham group; G-C (n = 2) for control of current apoptosis expression on the normal liver tissue. HBO was carried out using a transparent, cylindrical acrylic chamber with a pressure of 2.0 ATA. Hepatic samples were stained for caspase-3 cleavage.

: Apoptotic cells were identified in all groups. In the hepatic specimens of animals HBO-treated during ischemia (GHBO-I), there was a significant decrease (P < 0.001) in the number of cells undergoing apoptosis (1.62 +/- 0.91). The apoptotic index showed no significant difference in the animals HBO-treated during ischemia/reperfusion (5.75 +/- 1.28) compared with the G-I/R (3.5 +/- 0.75), which had no HBO treatment. The apoptosis index (11.25 +/- 1.90) was significantly higher (P < 0.01) in HBO-treated animals during the reperfusion period when compared with any of the other groups.

: A favorable effect was obtained when hyperbaric oxygen was administered early during ischemia. The hyperbaric oxygen in later periods of reperfusion was associated with a more severe apoptosis index. (c) 2009 Wiley-Liss, Inc. Microsurgery 2009.