[Energy metabolism of the isolated liver at subzero temperatures under the control of a newly developed system].
If the isolated liver could be preserved at subzero temperatures, it would keep viability for a longer time. But the liver is so large that it is difficult to cool and rewarm with an uniform heat distribution for minimizing differential effects of biochemical reactions. A new system was developed in order to cool and rewarm the liver uniformly. The apparatus consists of two heat exchangers, one temperature controller using a computer system and one hypothermic bath. The temperature of a perfusate and an immersing solution was controlled at the same time. Wistar rat livers were cooled to -4 degrees C and rewarmed to +4 degrees C by this system using 10% DMSO (Me2SO) solution. The perfusion pressure was 8-10 cmH2O and the liver temperature was uniformly controlled when the perfusion flow rate was 0.1 ml/g X liver/min and the temperature gradient was programmed at 2 degrees C/min. Levels of adenine nucleotides and histologic findings were evaluated in the livers which were cooled to -4 degrees C by this system and preserved for 24 hours. Levels of adenine nucleotides were higher in the liver preserved with -4 degrees C 10% DMSO Collins' M solution for 24 hours compared with those of +4 degrees C Collins' M for 24 hours and +4 degrees C lactated Ringer solution for 1 or 2 hours. Light microscopic findings of the liver preserved at -4 degrees C for 24 hours showed slight cellular atrophy and sinusoidal dilatation. But cellular and vascular structures appeared to be almost normally maintained. The liver preserved at +4 degrees C for 24 hours showed diffuse necrosis of liver cells and architectural destruction of the lobules. This system was useful for controlling the liver temperature in cooling and rewarming. The viability of livers at subzero temperatures controlled with this system was better than those above 0 degree C. This method may prolong the preservation period of the liver with a good viability.
D000818:Animals; D003080:Cold Temperature; D004734:Energy Metabolism; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014021:Tissue Preservation / Q000295:instrumentation*; D014022:Tissue Survival