Objectives: 

Our aim was to analyze the impact of ischemia-reperfusion during an experimental model of pancreas transplantation (PT) with enteric drainage of the exocrine secretion and systemic venous drainage on the fluidity of cell membranes isolated from the pancreas.

Materials: 

We used 12 Landrace pigs (six donors and six recipients). No immunosuppression was administered. Fluidity was measured by polarization changes of 1-(4- trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene-p-toluene sulfonate, and malonaldehyde (MDA) and 4-hydroxyalkenals (4-HDA) concentrations were used as an index of lipid oxidation. Tissue samples were collected from the left pancreatic lobe as follows: in the donor, immediately prior to vascular clamping (A); in the graft, following the ex situ perfusion-lavage with University of Wisconsin preservation fluid (UW) (B), and after 16 hr of cold ischemia (C); and, in the recipient, 30 min after vascular reperfusion (D). Mean differences were determined using a paired t-test, with the level of significance set to p ≤ 0.05.

Results: 

Membrane fluidity levels (1/polarization) and MDA + 4-HDA concentrations (nmol/mg protein) of the pancreatic biopsies were similar in cases A, B and C (membrane fluidity: A: 2.84 ± 0.12, B: 2.83 ± 0.13, C: 2.82 ± 0.15; MDA + 4-HDA: A: 0.11 ± 0.01, B: 0.14 ± 0.02, C: 0.17 ± 0.03). However, a significant rigidity and an increase of lipid peroxidation were found after 30 min of reperfusion (D: fluidity: 2.73 ± 0.16; MDA+4-HDA: 0.30 ± 0.06).

Conclusions: 

These findings suggest that reperfusion exaggerates oxidative damage and may account for the rigidity in the membrane of the pancreatic allografts during PT.