Protection of canine pancreatic microvascular endothelium against cold ischemic injury during preservation by the two-layer method.
BACKGROUND
Ischemic injury of the microvascular endothelium during cold preservation causes a disturbance of vascular microcirculation after reperfusion and results in graft failure. Recently we have shown that oxygenation of the canine pancreas during preservation by the two-layer method extends the period of preserved pancreatic viability. The aim of this study was to clarify the role of the oxygenation of the pancreas graft by the two-layer method in the viability of the microvascular endothelium during preservation.


METHODS
After preservation of the canine pancreas by simple cold storage in Euro-Collins solution (EC) (group 1) or by the two-layer method using EC (group 2) for 48 hr, the viability of vascular endothelial cells was judged from nuclear trypan blue uptake. Pancreatic tissue perfusions were measured with a hydrogen gas clearance technique, and graft survival rates were examined after autotransplantation. In the control group, the grafts were autotransplanted without preservation (group 3).


RESULTS
Graft survival rates were 0 of 5 (0%), 5 of 5 (100%), and 5 of 5 (100%) in groups 1, 2, and 3, respectively. The percentage of trypan blue-positive vascular endothelium in group 1 was significantly higher compared with group 3 (control) (26.4+/-1.7 vs. 7.4+/-4.3%, P<0.01). The two-layer method (group 2) decreased trypan blue uptake (11.3+/-3.7 vs. 26.4+/-1.7%, P<0.01). Pancreatic tissue perfusions after 2 hr of reperfusion were in inverse proportion to trypan blue uptake. Namely, pancreatic tissue perfusions in group 1 were significantly lower than group 3 (control) (45.6+/-12.8 vs. 64.5+/-20.6 ml/min/100 g, P<0.01). The two-layer method (group 2) improved pancreatic tissue perfusions (68.8+/-8.6 vs. 45.6+/-12.8 ml/min/100 g, P<0.01).


CONCLUSIONS
We conclude that oxygenation of the pancreas during preservation by the two-layer method protects the microvascular endothelium from cold ischemic injury. Consequently, pancreatic microcirculation can be maintained after reperfusion, thus extending the period of preserved pancreatic viability.
Kuroda
Y
Y
First Department of Surgery, Kobe University School of Medicine, Japan.
Fujita
H
H
Matsumoto
S
S
Suzuki
Y
Y
Kim
Y
Y
Tanioka
Y
Y
Ku
Y
Y
D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D002470:Cell Survival; D003922:Diabetes Mellitus, Type 1 / Q000601:surgery*; D004285:Dogs; D004730:Endothelium, Vascular / Q000166:cytology*; D005260:Female; D006085:Graft Survival / Q000502:physiology*; D006982:Hypertonic Solutions; D008297:Male; D008833:Microcirculation / Q000166:cytology / Q000502:physiology*; D009926:Organ Preservation / Q000379:methods*; D010179:Pancreas / Q000098:blood supply*; D016035:Pancreas Transplantation / Q000473:pathology / Q000502:physiology*; D015427:Reperfusion Injury / Q000517:prevention & control*; D014182:Transplantation, Autologous; D014343:Trypan Blue
C037096:Euro-Collins' solution; D006982:Hypertonic Solutions; D014343:Trypan Blue