Impact of Normothermic Preservation with Extracellular Type Solution Containing Trehalose on Rat Kidney Grafting from a Cardiac Death Donor

BACKGROUND: The aim of this study was to investigate factors that may improve the condition of a marginal kidney preserved with a normothermic solution following cardiac death (CD) in a model of rat kidney transplantation (RTx). METHODS: Post-euthanasia, Lewis (LEW) donor rats were left for 1 h in a 23°C room. These critical kidney grafts were preserved in University of Wisconsin (UW), lactate Ringer's (LR), or extracellular-trehalose-Kyoto (ETK) solution, followed by intracellular-trehalose-Kyoto (ITK) solution at 4, 23, or 37°C for another 1 h, and finally transplanted into bilaterally nephrectomized LEW recipient rats (n = 4-6). Grafts of rats surviving to day 14 after RTx were evaluated by histopathological examination. The energy activity of these marginal rat kidneys was measured by high-performance liquid chromatography (HPLC; n = 4 per group) and fluorescence intensity assay (n = 6 per group) after preservation with UW or ETK solutions at each temperature. Finally, the transplanted kidney was assessed by an in vivo luciferase imaging system (n = 2). RESULTS: Using the 1-h normothermic preservation of post-CD kidneys, five out of six recipients in the ETK group survived until 14 days, in contrast to zero out of six in the UW group (p<0.01). Preservation with ITK rather than ETK at 23°C tended to have an inferior effect on recipient survival (p = 0.12). Energy activities of the fresh donor kidneys decreased in a temperature-dependent manner, while those of post-CD kidneys remained at the lower level. ETK was superior to UW in protecting against edema of the post-CD kidneys at the higher temperature. Luminescence intensity of successful grafts recovered within 1 h, while the intensity of grafts of deceased recipients did not change at 1 h post-reperfusion. CONCLUSIONS: Normothermic storage with extracellular-type solution containing trehalose might prevent reperfusion injury due to temperature-dependent tissue edema

Impact of each preservation solution and temperature on tissue TAN and EC of preserved rat kidney.

<p>(A): The TAN of fresh kidneys at 37°C and CD1h at all temperatures were lower than that of fresh kidneys at 4°C and 23°C (* <i>p</i><0.05, fresh37 vs. fresh4 in UW; # <i>p</i><0.05, fresh37 vs. fresh4 and 23 in ETK). (B) The EC of the fresh37, CD1h4, CD1h23, and CD1h37 groups was not higher than that of the fresh4 and fresh23 groups. The EC of fresh23 with UW preservation was significantly lower than that of fresh4 (* <i>p</i><0.05).</p

Determination of fluorescence intensity of kidney chips.

<p>The fluorescence intensity of the UW group at 6 h after preservation was significantly higher than that of the ETK group (* <i>p</i><0.05). However, the fluorescence intensity of both groups was approximately equal at 24 h. (# <i>p</i><0.05 vs. ETK group).</p

Differentiation of survival time under each preservation condition.

*<p>vs. CD1h <i>p</i><0.01 using Log-Rank test.</p>#<p>vs. ETK23 <i>p</i><0.01 using Log-Rank test.</p>##<p>vs. ETK23 <i>p</i><0.05 using Log-Rank test.</p>†<p>vs. ITK23 <i>p</i><0.01 using Log-Rank test.</p><p>ETK, ET-Kyoto solution; UW, University of Wisconsin solution; LR, lactate Ringer's solution; ITK, IT-Kyoto solution.</p

Survival rate, blood urea nitrogen (BUN) and serum creatinine (Cre) levels in experiment 1.

<p>(A): Survival rate of each group. Survival rate of the CD1h group was significantly greater than that of the 2-h post-CD group (* <i>p</i><0.01 using Log-Rank test.). (B): BUN. (C): Cre. BUN and Cre levels of all surviving rats were gradually recovered to a normal range by day 14 after RTx.</p

Compositions of ETK, ITK, UW or LR.

<p>Compositions of ETK, ITK, UW or LR.</p

Pathological status of kidney graft after kidney transplantation (RTx).

<p>After euthanasia on day 14 after RTx, kidneys were harvested and stained with azan stain for parenchymal fibrosis. Fibrosis was graded numerically as follows; (A): 0 = none, (B): 1 = minimal, (C): 2 = moderate, and (D): 3 = severe. In each slide, 20 fields were evaluated by four observers blinded to treatment (4×20 fields). Fibrosis of the group receiving kidneys preserved with ETK23 tended to be lower than that of the other groups, but the difference was not significant (<i>p</i>>0.05).</p

Survival rate, blood urea nitrogen (BUN) and serum creatinine (Cre) levels in experiment 2.

<p>(A): Survival rate of each group. Survival rate of the group receiving kidneys preserved with ET-Kyoto solution (ETK) for 1 h at 23°C (ETK23 group) was significantly longer than that of the other groups (# <i>p</i><0.01 using Log-Rank test.). (B): BUN and (B'): Cre of the ETK23 group. (C): BUN and (C'): Cre of the other groups without EK23. In all groups in experiment 2, BUN and Cre of all surviving rats reached a peak at day 2 and recovered to a nearly normal range by day 14. (BUN and Cre of the LR23 group was n = 1 after day 4.)</p