Effects of preservation conditions and temperature on tissue acidification in canine kidneys

The influence of temperature (5, 15, 25, and 35 degrees C) on the degree of tissue acidification was examined using 74 canine kidneys with simple ischemia or after protection of the kidneys with Euro-Collins solution or with the HTK-solution of Bretschneider. At an incubation temperature of 5 degrees C, the intrarenal pH value in HTK-protected kidneys is continuously higher than 7.3 during 36 hr of ischemia. In Euro-Collins kidneys the pH value decreases to a pH of 6.4 during this time. In simple ischemic kidneys pH is 6.3 after 36 hr. At 15 degrees C the pH value falls to a lower level in Euro-Collins kidneys than in purely ischemic kidneys, but the pH in HTK-protected kidneys is higher than 6.9 for 24 hr. At 25 degrees C, and especially at 35 degrees C the intrarenal acidosis in Euro-Collins kidneys is much stronger than in unprotected kidneys, and the pH in HTK-protected kidneys does not decrease below 6.7. The lactate production in simple ischemic kidneys and in HTK-protected kidneys is nearly the same (80-100 mumol/gdw), although Euro-Collins kidneys have a steeper increase and reach higher lactate levels (330 mumol/gdw). The HTK solution guarantees satisfactory protection against damaging acidosis over the whole temperature range (5-35 degrees C), but the Euro-Collins solution leads to a stronger and more dangerous acidosis the higher the temperature.