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Redefining the properties of an osmotic agent in an intestinal-specific preservation solution
Kimberly Schlachter1, Matthew S Kokotilo, Jodi Carter
1Department of Surgery, University of Alberta, 2D2.28 Walter Mackenzie Center, Edmonton, Alberta, T6G 2B7, Canada.
Aim:
To investigate the effects of dextrans of various molecular weights (Mw) during a 12 h cold storage time-course on energetics, histology and mucosal infiltration of fluorescein isothiocyanate (FITC)-dextran.
Methods:
Rodent intestines were isolated and received a standard University of Wisconsin vascular flush followed by intraluminal administration of a nutrient-rich preservation solution containing dextrans of varying Mw: Group D1, 73 kdal; Group D2, 276 kdal; Group D3, 534 kdal; Group D4, 1185 kdal; Group D5, 2400 kdal.
Results:
Using FITC-labeled dextrans, fluorescent micrographs demonstrated varying degrees of mucosal infiltration; lower Mw (groups D1-D3: 73-534 kdal) dextrans penetrated the mucosa as early as 2 h, whereas the largest dextran (D5: 2400 kdal) remained captive within the lumen and exhibited no permeability even after 12 h. After 12 h, median injury grades ranged from 6.5 to 7.5 in groups D1-D4 (73-1185 kdal) representing injury of the regenerative cryptal regions and submucosa; this was in contrast to group D5 (2400 kdal) which exhibited villus denudation (with intact crypts) corresponding to a median injury grade of 4 (P < 0.05). Analysis of tissue energetics reflected a strong positive correlation between Mw and adenosine triphosphate (r(2) = 0.809), total adenylates (r(2) = 0.865) and energy charge (r(2) = 0.667).
Conclusion:
Our data indicate that dextrans of Mw > 2400 kdal act as true impermeant agents during 12 h ischemic storage when incorporated into an intraluminal preservation solution.
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