Co-administration of melatonin and dexamethasone attenuates lung tissue injury after liver ischemia/reperfusion

Ischemia-reperfusion injury (IRI) is a common and important clinical problem in many different organ
systems. Once the blood flow and oxygen supply are reestablished, reperfusion enhances the injury caused by the
ischemic period .This phenomenon, known as ischemia/reperfusion (IR) injury, impacts directly on liver viability,
especially during transplantation and liver surgery. The purpose of this study was to evaluate combination
pretreatment of melatonin (MEL) and dexamethasone (DEX) on liver I/R model of lung injury. Male Wistar rats
(n=60) were assigned to 5 groups of 12 animals each: 1: Sham; Laparatomy without I/R 2: I/R; underwent hepatic
I/R. 3: I/R+MEL; hepatic I/R+ injected intraperitoneally melatonin (20 mg/kg). 4: I/R+DEX; hepatic I/R+ injected
intravenously dexamethasone (10 mg/kg). 5: I/R+MEL+DEX; hepatic I/R+ injected intraperitoneally melatonin +
injected intravenously dexamethasone. Liver subjected to ischemia by clamping portal triad for 30 minutes and was
reperfused for 6 hours after ischemia by removing the clamps. Levels of glutathione peroxidase (GPx) and
superoxide dismutase (SOD) decreased after hepatic I/R in all groups; levels of GPx and SOD were higher in
I/R+MEL+DEX group comparing to I/R, I/R+MEL and I/R+DEX groups significantly(P<0.05), and they were
higher in I/R+MEL group comparing to I/R and I/R+DEX groups but it was not significant. Lung tissue
malondialdehyde (MDA) ,lung injury index, and apoptotic index increased after hepatic I/R. Tissue MDA, tissue
injury index and apoptotic index were lower in I/R+MEL+DEX group comparing to I/R, I/R+MEL and I/R+DEX
groups significantly(P<0.05), and in I/R+MEL was lower than I/R+DEX group but it was not significant. Coadministration
of melatonin and dexamethasone had better results in decreasing the lung injury after hepatic I/R ,
comparing to administering each of them alone.
[Mohammad Taghizadieh, Babak Hajipour, Naser Ahmadi Asl, Ali Khodadadi, Mohammad Hossein Somi. Coadministration
of Melatonin and Dexamethasone Attenuates Lung Tissue Injury after Liver
Ischemia/Reperfusion.