Lee D, Walker J M
Transplantation. 1977 Feb;23(2):136-41. doi: 10.1097/00007890-197702000-00005.
Isolated rat liver was studied before, during, and after hypothermic perfusion at 5 C for 24, 48, or 72 hr with an acellular perfusate consisting of 7% bovine serum albumin in Kreb-Ringer buffer containing glucose, penicillin, and streptomycin. Bile production ceased at 5 C but resumed when the temperature was raised to 35 C. The rate of flow and the total amount produced was unaffected by 24 hr of hypothermia but decreased when the cooling period was extended to 48 and 72 hr. The data of other workers was used to show a correlation between bile flow and oxygen consumption by the liver. Cooling also caused the release of potassium into the perfusate but it was quickly reaccumulated after rewarming; however, the extent and rate of reaccumulation decreased as the cooling period increased, as did the ability of the livers to retain the ion. Urea synthesis did not cease after cooling and after rewarming, the rate of synthesis increased as the period of hypothermia was lengthened. The maximum concentration of urea in the perfusate was found when rewarmed livers had produced 200 mumol of urea but at this point, control livers had produced 280 mumol. The concentration of glucose in the perfusate of livers maintained at 35 C showed peaks at 2 and 9 to 10 hr after the start of perfusion. After cooling for 24 hr these peaks arose at 2 and 7 hr after rewarming, but with 48 hr of hypothermia, these peaks were higher and appeared at 2 and 4 hr. When the cooling period was extended to 72 hr, only a single peak was seen 2 hr after rewarming. These results suggest that rat liver can be cooled to 5 C for 24 hr with little effect on its functional characteristics but a marked decline becomes apparent when the cooling period is extended beyond 24 hr. None of the livers studied was transplanted after perfusion and it remains to be seen how the functional tests conducted in vitro correlate with the ability of the livers to support life.
研究了离体大鼠肝脏在5℃下用无细胞灌注液进行低温灌注24、48或72小时之前、期间和之后的情况，该灌注液由含葡萄糖、青霉素和链霉素的Kreb-Ringer缓冲液中的7%牛血清白蛋白组成。在5℃时胆汁分泌停止，但温度升至35℃时胆汁分泌恢复。流速和分泌总量在24小时低温灌注时不受影响，但当冷却时间延长至48和72小时时降低。利用其他研究者的数据显示了肝脏胆汁流动与氧消耗之间的相关性。冷却还导致钾释放到灌注液中，但复温后钾很快重新蓄积；然而，随着冷却时间的增加，重新蓄积的程度和速率降低，肝脏保留离子的能力也降低。冷却后尿素合成并未停止，复温后，合成速率随着低温时间的延长而增加。当复温肝脏产生200 μmol尿素时，灌注液中尿素的最大浓度出现，但此时对照肝脏已产生280 μmol。维持在35℃的肝脏灌注液中葡萄糖浓度在灌注开始后2小时以及9至10小时出现峰值。冷却24小时后，这些峰值在复温后2小时和7小时出现，但低温48小时后，这些峰值更高且出现在2小时和4小时。当冷却时间延长至72小时时，复温后2小时仅出现一个峰值。这些结果表明，大鼠肝脏可冷却至5℃达24小时，对其功能特性影响很小，但当冷却时间延长超过24小时时，明显的功能衰退就会出现。所研究的肝脏在灌注后均未进行移植，体外进行的功能测试与肝脏支持生命能力之间的相关性还有待观察。
