The effect of calcium in the UW solution on preservation of the rat liver

In this study we investigated the effect of calcium addition to the UW solution on the quality of the preserved rat liver as judged by normothermic isolated perfusion. Rat livers were cold stored in UW solution containing varying concentrations of calcium chloride (0, 0.5, 1.5, 5.0 mM) for periods of 0, 24 and 48 hours. At the end of the preservation period the livers were reperfused for 90 minutes at 37 degrees C with Krebs Henseleit Buffer. The quality of preservation was assessed by quantification of enzyme release, bile production and protein synthesis. The addition of 1.5 mM calcium to the UW solution suppressed the incidence of damage in the 24 hour cold stored liver similar to control livers (0 hours preserved). LDH release were significantly reduced from 22.1 +/- 7.3 (units/hr/g) in regular UW to 9.4 +/- 0.8 (units/hr/g) in UW plus 1.5 mM calcium. AST release also was suppressed by the addition of calcium to the UW. Bile production was enhanced by the addition of calcium; from 21.3 +/- 0.6 (mg/hr/g) in regular UW to 46.3 +/- 5.9 (mg/hr/g) in UW plus 1.5 mM calcium. Protein synthesis was reduced to 38% of control after 24 hr cold storage and was unchanged by the addition of calcium to the preservation solution. Although the addition of calcium to the UW solution improved the preservation of the 24 hour cold stored liver it did not offer the same degree of protection to the 48 hour preserved liver. Therefore, calcium addition may be one agent for improving preservation for short term cold storage of the liver but longer term storage will require other modifications as well.