Banker M C, Layne J R, Hicks G L, Wang T
Department of Surgery, University of Rochester, N.Y. 14642.
J Heart Lung Transplant. 1992 Jul-Aug;11(4 Pt 1):619-23.
Isolated rat hearts perfused with hyperosmotic Krebs-Henseleit buffer containing 60 mmol/L NaCl lose 10% of their tissue water. Perfusion of the rat hearts with Krebs-Henseleit buffer containing polyethylene glycol 8000 caused a concentration-dependent reduction in tissue water. In a study of the effect of different cryoprotectants on cardiac preservation, isolated rat hearts were flushed with a cardioplegic solution (CP-14), or CP-14 with either 50 mmol/L glycerol (CP-15), or 5% polyethylene glycol (CP-16) and frozen at -1.4 degrees C for 5 hours. Thawed hearts were reperfused in working mode to assess function. There was no recovery in CP-14 hearts. Hearts treated with CP-15 recovered 39.3% +/- 2.9% (mean +/- SEM) of control cardiac output. CP-16 boosted the recovery of cardiac output to 54.4% +/- 5.7% (p less than 0.05 vs CP-15). Glycerol significantly reduced tissue ice content; PEG further decreased the ice content to 31.7% +/- 0.6%, which was distinctively lower than that in CP-14 (44.7% +/- 1.1%) and in CP-15 hearts (34.6% +/- 1.1%). Tissue water content of CP-14 and CP-15 hearts was similar (3.83 and 3.87 gm H2O/gm dry weight). Polyethylene glycol reduced the tissue water content to 3.24 +/- 0.04 gm H2O/gm dry (p less than 0.01 vs CP-14 and CP-15 by ANOVA). Thus both glycerol and polyethylene glycol offered cryoprotection to the heart explant by reducing tissue ice formation. Polyethylene glycol was superior to glycerol by dehydrating myocardial tissue and further minimizing freezing damage.
用含60 mmol/L氯化钠的高渗克雷布斯 - 亨塞尔特缓冲液灌注的离体大鼠心脏会失去其组织水分的10%。用含聚乙二醇8000的克雷布斯 - 亨塞尔特缓冲液灌注大鼠心脏会导致组织水分呈浓度依赖性减少。在一项关于不同冷冻保护剂对心脏保存效果的研究中，离体大鼠心脏先用心脏停搏液（CP - 14）冲洗，或者用含50 mmol/L甘油的CP - 14（CP - 15）或含5%聚乙二醇的CP - 14（CP - 16）冲洗，然后在 - 1.4℃冷冻5小时。解冻后的心脏在工作模式下再灌注以评估功能。CP - 14组心脏没有恢复。用CP - 15处理的心脏恢复了对照心输出量的39.3%±2.9%（平均值±标准误）。CP - 16将心输出量的恢复提高到54.4%±5.7%（与CP - 15相比，p＜0.05）。甘油显著降低了组织冰含量；聚乙二醇进一步将冰含量降低至31.7%±0.6%，明显低于CP - 14组（44.7%±1.1%）和CP - 15组心脏（34.6%±1.1%）。CP - 14组和CP - 15组心脏的组织含水量相似（分别为3.83和3.87克水/克干重）。聚乙二醇将组织含水量降低至3.24±0.04克水/克干重（方差分析显示与CP - 14和CP - 15相比，p＜0.01）。因此，甘油和聚乙二醇都通过减少组织冰的形成对离体心脏提供了冷冻保护。聚乙二醇通过使心肌组织脱水并进一步将冷冻损伤降至最低，优于甘油。
