Skibba J L, Powers R H, Stadnicka A, Cullinane D W, Almagro U A, Kalbfleisch J H
Ellis Fischel Cancer Center, University of Missouri Health Sciences Center, Department of Surgery, Columbia 65203.
Int J Hyperthermia. 1991 Sep-Oct;7(5):749-61. doi: 10.3109/02656739109056444.
Heat-induced hepatotoxicity accompanying hyperthermic liver perfusion was studied in the isolated, haemoglobin-free perfused rat liver. Trypan blue uptake, a sensitive indicator of cell death, was used to examine the relationship between the efflux of oxidized glutathione (oxidative stress), the appearance of cytosolic enzymes in the perfusate and cell death. Livers were perfused at 37, 42, 42.5 and 43 degrees C. The efflux of total glutathione (GSH) and oxidized glutathione (GSSG) increased with time and temperature. Differences between temperature groups were significant for both parameters for 37 versus 42, 42.5 and 43 degrees C (p less than 0.05). Temperature-related differences in GSH levels appeared at 15 min for 37 versus 42 degrees C and in GSSG levels at 30 min for 37 versus 42 and 42.5 degrees C. Biliary excretion of total GSH increased from 72 nmol at 37 degrees C to 144 nmol at 42 degrees C, 160 nmol at 42.5 degrees C and 124 nmol at 43 degrees C, which was significant for 37 versus 42 and 42.5 degrees C (p less than 0.05). The release of allantoin into the perfusate, a measure of purine catabolism and flux through xanthine oxidase, was increased at 42, 42.5 and 43 degrees C compared to 37 degrees C (p less than 0.05). Liver injury was assessed by measuring the release of asportate aminotransferase (AST) and lactate dehydrogenase (LDH) and uptake of trypan blue after perfusion at each temperature. There was a pronounced release of LDH and AST into the perfusate after 60 min of perfusion at 42, 42.5 and 43 degrees C, the levels of which were significantly different from the 37 degrees C mean level. There was no uptake of trypan blue after 60 min perfusion at 37 degrees C. Perfusion at 42, 42.5 and 43 degrees C resulted in the uptake of trypan blue in the pericentral areas, but the dye uptake was significant (p less than 0.05) compared to 37 degrees C at 42.5 and 43 degrees C only. These data show that heat-induced pericentral cell death is minimal after 60 min at 42-43 degrees C, and that the biochemical process which occurred during this period suggest 'oxidative stress' as a causative factor in hyperthermic hepatotoxicity. In addition, this liver toxicity is probably related to xanthine oxidase activity or the depletion of GSH as the initiating event which leads to lipid peroxidation and cellular damage.
在离体无血红蛋白灌注大鼠肝脏中研究了热灌注诱导的肝毒性。用台盼蓝摄取这一细胞死亡的敏感指标，来检测氧化型谷胱甘肽外流（氧化应激）、灌流液中胞质酶的出现与细胞死亡之间的关系。肝脏分别在37、42、42.5和43℃下进行灌注。总谷胱甘肽（GSH）和氧化型谷胱甘肽（GSSG）的外流随时间和温度升高而增加。37℃与42、42.5和43℃组之间，这两个参数的差异均具有统计学意义（p<0.05）。37℃与42℃组在15分钟时出现GSH水平的温度相关差异，37℃与42℃和42.5℃组在30分钟时出现GSSG水平的温度相关差异。总GSH的胆汁排泄量从37℃时的72 nmol增加到42℃时的144 nmol、42.5℃时的160 nmol和43℃时的124 nmol，37℃与42℃和42.5℃组之间差异具有统计学意义（p<0.05）。与37℃相比，42、42.5和43℃时，灌流液中尿囊素的释放增加，尿囊素是嘌呤分解代谢和通过黄嘌呤氧化酶的通量的指标（p<0.05）。通过测量各温度下灌注后天冬氨酸转氨酶（AST）和乳酸脱氢酶（LDH）的释放以及台盼蓝的摄取来评估肝损伤。在42、42.5和43℃下灌注60分钟后，LDH和AST大量释放到灌流液中，其水平与37℃时的平均水平有显著差异。在37℃下灌注60分钟后没有台盼蓝摄取。在42、42.5和43℃下灌注导致中央静脉周围区域摄取台盼蓝，但仅在42.5和43℃时与37℃相比，染料摄取具有统计学意义（p<0.05）。这些数据表明，在42 - 43℃下60分钟后热诱导的中央静脉周围细胞死亡最小，并且在此期间发生的生化过程表明“氧化应激”是热诱导肝毒性的致病因素。此外，这种肝毒性可能与黄嘌呤氧化酶活性或GSH耗竭有关，这是导致脂质过氧化和细胞损伤的起始事件。
