Apoptosis of rat liver in cold preservation with custom-designed KYL solution

BACKGROUND: A suitable perfusate is very important in reducing various problems in liver preservation, prolonging the time of organ preservation and enhancing the quality of donor tissue. University of Wisconsin (UW) solution is the most successful solution for preserving multiple organs at present, but it has many shortcomings. We set out to develop a new liver preservation solution (KYL solution) and study its effects on apoptosis in rat liver undergoing cold preservation. METHODS: Using non-circulated isolated perfused rat liver (IPRL), we randomly preserved Sprague-Dawley rat livers for 0, 4, 8, 16, 24, and 48 hours with KYL solution or UW solution. The effects were assessed by measuring the content of free radicals in Krebs-Henseleit solution and the intracellular calcium content of hepatocytes, assessing hepatocellular apoptosis and related-gene expression, and observing the morphological changes in liver. To evaluate the protection by KYL and UW solutions in rat liver perfusion and preservation, we chosed normal saline for negative comparison. RESULTS: The intracellular calcium content of the liver preserved in KYL solution was less than that preserved in UW solution. At every different period of preservation, the malonaldehyde and superoxide dismutase content in Krebs-Henseleit solution, the percentage of apoptotic cells and the expression patterns of apoptosis-related-genes were similar in livers preserved in KYL and UW solutions. Morphological changes in the two groups were almost the same. The variables in both groups were better than those of livers preserved in normal saline. Both KYL and UW solutions protected rat liver from ischemia-reperfusion injury. CONCLUSIONS: KYL solution is superior to UW solution in preventing calcium overload. More severe hepatocyte damage may appear in the KYL group than in the UW group and the effect of KYL solution on apoptosis in rat liver preservation is similar to that of UW solution.

Experimental Study on the Cryopreservation of LLC-PK1 Epithelial Cells with Hypoxic UW Solution

The effects of oxygen partial pressure on cryopreservation of the cells with organ preservation solution were explored. Hypoxic UW solution was made by purging the UW solution with argon. The pig proximal tubule epithelial cells （LLC-PK1 cells） were cryopreserved in hypoxic UW solution （Ar-UW group） or standard UW solution （UW group） at 4℃ for 48 h. Trypan blue staining and LDH detection were performed to evaluate the injury of the cells. The results showed that the oxygen partial pressure in Ar-UW group was significantly declined from 242±6 mmHg to 83±10 mmHg. After cryopreservation at 4℃ for 48 h, LDH leakage rate and Trypan blue-stained rate in Ar-UW group were （11.3±3.4）% and （10.5±4.7）%, respectively, which were significantly lower than in UW group [（49.5±6.9）% and （47.6±9.3）% respectively, both P〈0.01]. It was concluded that lower oxygen partial pressure of UW solution was more beneficial to the cryopreservation of LLC.

Preparation and Preservation of Hypoxia UW Solution

In order to explore the method to prepare hypoxia UW solution and the stability and preservation of hypoxia UW solution, UW solution was purged by argon or air for 15 min or 60 at a flow rate of 0.8 or 2 L/min, and the oxygen partial pressure of UW solution was detected. The hypoxia UW solution was exposed to the air or sealed up to preserve by using different methods, and the changes of oxygen partial pressure was tested. The results showed that oxygen partial pressure of 50 mL UW solution, purged by argon for 15 min at a flow rate of 2 L/min, was declined from 242±6 mmHg to 83±10 mmHg. After exposure to the air, oxygen partial pressure of hypoxia UW solution was gradually increased to 160±7 mmHg at 48 h. After sealed up by the centrifuge tube and plastic bad filled with argon, oxygen partial pressure of hypoxia UW solution was stable, about 88±13 mmHg at 72 h. It was concluded that oxygen of UW solution could be purged by argon efficiently. Sealed up by the centrifuge tube and plastic bag filled with argon, oxygen partial pressure of UW solution could be stabilized.

A study on continuous low-flow perfusion with low-potassium dextran for donor isolated lung preservation

OBJECTIVE: To test the validity of continuous low-flow perfusion with low-potassium dextran (LPD) to preserve rabbit lung. METHODS: Isolated rabbit lungs were preserved for eight hours either in Ringer's solution by simple storage (Group I) or in continuous low-flow perfusion with LPD (Group II). After preservation, lung functions were assessed to compare these two methods. RESULTS: The water gain in Group I was higher than that in Group II. During reperfusion, the functional test values for the immersed lungs were lower than those for the perfused lungs. The lipid peroxidation product (MDA) was significantly decreased in perfused lungs during reperfusion. CONCLUSIONS: Low-flow perfusion with LPD is better than immersion for the lung preservation.