Glycine ameliorates lung reperfusion injury after cold preservation in an ex vivo rat lung model.
BACKGROUND
The role of glycine has not been investigated in lung ischemia-reperfusion injury after cold preservation. Furthermore, the role of apoptosis after reperfusion following cold preservation has not been fully understood.


METHODS
Lewis rats were divided into three groups (n=6 each). In the GLY(-) and GLY(+) groups, isolated lungs were preserved for 15 hr at 4 degrees C after a pulmonary artery (PA) flush using our previously developed preservation solution (ET-K; extracellular-type trehalose containing Kyoto), with or without the addition of glycine (5 mM). In the Fresh group, isolated lungs were reperfused immediately after a PA flush with ET-K. They were reperfused for 60 min with an ex vivo perfusion model. Pulmonary function, oxidative stress, apoptosis, and tumor necrosis factor (TNF)-alpha expression were assessed after reperfusion.


RESULTS
Shunt fraction and peak inspiratory pressure after reperfusion in the GLY(-) group were significantly higher than those in the GLY(+) and Fresh groups. Oxidative damage and apoptosis in the alveolar epithelial cells of the GLY(-) group, assessed by immunohistochemical staining and quantification of 8-hydroxy-2'-deoxyguanosine and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling method, were significantly higher than those of the GLY(+) and Fresh groups. There were correlations among shunt fraction, oxidative damage, and apoptosis. There was no expression of TNF-alpha messenger RNA in all groups evaluated by the reverse transcription-polymerase chain reaction.


CONCLUSIONS
Glycine attenuates ischemia/reperfusion injury after cold preservation by reducing oxidative damage and suppressing apoptosis independent of TNF-alpha in this model. The suppression of apoptosis might ameliorate lung function after reperfusion.
Omasa
Mitsugu
M
Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Fukuse
Tatsuo
T
Toyokuni
Shinya
S
Mizutani
Yoichi
Y
Yoshida
Hiroshi
H
Ikeyama
Kazuyuki
K
Hasegawa
Seiki
S
Wada
Hiromi
H
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D017209:Apoptosis; D001794:Blood Pressure; D015925:Cryopreservation; D019610:Cytoprotection; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D005998:Glycine / Q000494:pharmacology*; D007150:Immunohistochemistry / Q000379:methods; D020287:In Situ Nick-End Labeling; D001239:Inhalation; D007511:Ischemia / Q000503:physiopathology; D008168:Lung / Q000378:metabolism; D008297:Male; D018384:Oxidative Stress; D011312:Pressure; D011651:Pulmonary Artery / Q000503:physiopathology; D011652:Pulmonary Circulation; D051381:Rats; D011917:Rats, Inbred Lew; D015427:Reperfusion Injury / Q000503:physiopathology*; D013194:Staining and Labeling
D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine; D005998:Glycine