To evaluate the influence on lung preservation of potassium ion concentration in an organ preservation solution, four types of solutions were produced for the present study. These preservation solutions consisted of sodium and potassium ions as cation (Na^+ ; 155 mmoI, K^+ ; 0 in solution 1, Na^+ ; 150, K^+ ; 5 in solution 2, Na^+ ; 20, K^+ ; 135 in solution 3, Na^+ ; 0, K^+ ; 155 in solution 4), and phosphate ion as anion, with glucose, They possess the same osmolarity, the same pH in the same temperature and the same buffer action. The lungs were preserved at 7^+C with these solutions for 24 hours and evaluated in a rat lung perfusion system with perfluorochemical emulsion.
The recovery rates of pulmonary arterial flow were better in low (but not zero) potassium solutions. On the other hand, wet-to-dry ratios were kept lower in high potassium solutions. The recovery rates of tidal volume and oxygen tension of pulmonary venous effluent showed no significant difference in each group. In conclusion, potassium ion concentration does not play a major role in lung preservation in this system.