Glycine intravenous donor preconditioning is superior to glycine supplementation to low-potassium dextran flush preservation and improves graft function in a large animal lung transplantation model after 24 hours of cold ischemia.
OBJECTIVE
The potential role of glycine in combination with standard lung preservation with low-potassium dextran solution in lung ischemia-reperfusion injury has not been investigated in a preclinical porcine transplant model.


METHODS
In a control group (n = 6), donor lungs were flushed with 1 liter of low-potassium dextran solution. In a second group (LPD-glyc, n = 6), low-potassium dextran solution was supplemented with 3.75 g of glycine. In a third group (IV-glyc, n = 6), donor preconditioning was performed by intravenous administration of 3.75 g glycine 1 hour before low-potassium dextran preservation. Grafts were stored in low-potassium dextran at 4 degrees C for 24 hours. Posttransplant graft function was assessed throughout a 7-hour observation period.


RESULTS
In the control group, 2 recipients died of right-sided heart failure caused by severe ischemia-reperfusion injury. All animals of the glycine groups survived the entire observation period. Pulmonary vascular resistance remained significantly (P < .01) lower in both glycine groups when compared with controls. At the end of the observation period pulmonary vascular resistance in the control group was higher (P < .01) compared with the glycine groups (1310 +/- 319 dyn x sec x cm(-5) vs 879 +/- 127 dyn x sec x cm(-5) [LPD-glyc] vs 663 +/- 191 dyn x sec x cm(-5) [IV-glyc]). Changes of lung tissue water content were lower in the IV-glyc group compared with the LPD-control (P < .01) and LPD-glyc lungs (P < .05). Oxygenation (PO2/FiO2) was higher in the IV-glyc group compared with the LPD-glyc and control lungs (445 +/- 110 mm Hg vs 388 +/- 124 mm Hg [P < .01] vs 341 +/- 224 mm Hg [P < .001], respectively).


CONCLUSIONS
Modification of low-potassium dextran solution with glycine or donor preconditioning ameliorates ischemia-reperfusion injury in lung transplantation. This intriguing approach merits further evaluation with respect to the mechanisms involved and may improve results in clinical lung preservation.
Gohrbandt
Bernhard
B
Hannover Thoracic Transplant Program, Division of Cardiothoracic and Vascular Surgery, Hannover Medical School, Hannover, Germany.
Fischer
Stefan
S
Warnecke
Gregor
G
Avsar
Murat
M
Sommer
Sebastian P
SP
Haverich
Axel
A
Strueber
Martin
M
D000818:Animals; D050377:Cold Ischemia; D003911:Dextrans; D005947:Glucose; D005998:Glycine / Q000008:administration & dosage*; D007275:Injections, Intravenous; D016040:Lung Transplantation / Q000502:physiology*; D023421:Models, Animal; D009926:Organ Preservation; D019188:Organ Preservation Solutions; D015427:Reperfusion Injury / Q000517:prevention & control*; D013552:Swine; D013997:Time Factors; D014019:Tissue Donors
D003911:Dextrans; D019188:Organ Preservation Solutions; C083290:low potassium dextran glucose solution; D005947:Glucose; D005998:Glycine