Study On The Application Of Polymerized Porcine Hemoglobin In Small Bowel Preservation

Objective:Hypertonic citrate adenine solution (HCA) has been used in the field of kidney transplantation and small bowel preservation in our country for many years and exhibits good effect. Polymerized porcine hemoglobin (pPolyHb) has been developed to carry and transport oxygen to the tissues effectively. Therefore preservation solutions containing pPolyHb maybe improve organ preservation. In this study we compared the effects of UW, HCA and pPolyHb+HCA on the rheologic parameters of rat RBC at37℃and rat small intestinal graft preservation effect at4℃.Methods:Whole blood viscosity and rat RBC aggregability were measured using an automated dynamic shear rheometer with cone-plane geometry. Bright field microsc-opy was used to observe the changes of RBC morphology and aggregation.Small bowel (SB) from Sprague-Dawley rats (n=6in each group) were procured according to standardized procedures involving vascular flush with hypertonic citrate a denine solution and luminal treatment with NaCl solution. SB were assigned randomly to the following groups:group1:HCA; group2:pPolyHb (2g/dl)+HCA; group3:p-PolyHb(4g/dl)+HCA;group4:UW solution. ATP, oxidative stress, PO2, pH, Lac, lacta-te dehydrogenase(LDH) and histology were assessed over36hours at4℃.Results:The mean RBC aggregation index (AI) was6.99±1.15in pure blood con-trol samples,6.68±1.26in UW group,4.56±1.41in pPolyHb (1g/dl)+HCA group, an-d4.76±0.08in pPolyHb (5g/dl)+HCA group, respectively. The concentration of pPoly-Hb (0.5g/dL, lg/dL and5g/dL) in the HCA had little effect on RBC aggregation, w-hile UW solution significantly increased the RBC blood viscosity and had a hyperagg-regating effect on RBC.Grafts from group2and group3showed significantly lower injury scores compared to group1and group4at12and24hours, a difference that disappeared at36hours of preservation, except group2. pH, Lac data, correlated well with histologic damage. The addition of pPolyHb in HCA solution resulted in a significant higher malondialde-hyde levels compared with all other preservation solution throughout36hours of cold storage. Grafts ATP concentration was significantly higher in Group2and Group3co-mpared to that in Group1and Group4during cool storage.Conclusion:Concentration of pPolyHb (5g/dl) in HCA solution would be the opti mal choice for flushing the donor organ. HBOCs can supply a greater amount of oxy-gen to HCA solution. Indirect measures of oxygen metabolism such as ATP content and lactate production suggested improvement of pPolyHb in maintaining graft oxygen metabolism.