Novitzky D, Wicomb W N, Cooper D K, Tjaalgard M A
Cryobiology. 1987 Feb;24(1):1-10. doi: 10.1016/0011-2240(87)90002-2.
Deterioration of function in brain dead baboons is associated with depletion of both myocardial energy stores and certain circulating hormones, notably thyroxine, cortisol, and insulin. We have therefore investigated the effect of the administration of these three hormones to the brain dead pig; their value has been assessed on both the freshly excised and stored donor heart. Brain death was induced by ligation of the two arteries to the upper part of the body which arise from the aortic arch. Storage of selected hearts was by continuous hypothermic perfusion for 20 to 24 hr. Hearts were biopsied for estimation of adenosine triphosphate, creatine phosphate, lactate, and glycogen, and were subsequently functionally tested. Six groups of pigs were studied. Hearts were tested from control pigs which had not undergone brain death (A1), from brain dead pigs which had received intravenous fluid and inotropic support for 4 hr (B1), and from brain dead pigs which had in addition received 2 hr of hormonal therapy (thyroxine 2 micrograms cortisol 100 mg, and insulin 5-10 IU hourly) (C1). A further 3 groups (A2-C2) underwent management identical to A1-C1, but in addition the hearts were stored for 24 hr. Brain death in pigs was followed by a consumption of myocardial energy stores, despite anaerobic glycolysis; this was associated with reduced myocardial function. The administration of hormones to the brain dead pig led to some replenishment of myocardial energy and glycogen reserves and reduction in lactate, with associated improvement in hemodynamic function. A period of hypothermic perfusion storage appeared to reverse the anaerobic metabolism occurring in the heart in the nonhormonally treated brain dead animal, though not in the hormonally treated animal, and led to replenishment of glycogen reserves in nontreated animals. The observation that both better function and an increase in myocardial energy stores occurred in hormonally treated, stored hearts, even though perfusate lactate dehydrogenase rose to significantly higher levels during hypothermic perfusion storage, and tissue lactate levels remained high, suggests that thyroxine promotes both aerobic and anaerobic metabolism in brain dead animals.
脑死亡狒狒的功能恶化与心肌能量储备和某些循环激素（特别是甲状腺素、皮质醇和胰岛素）的耗竭有关。因此，我们研究了向脑死亡猪施用这三种激素的效果；已在新鲜切除和保存的供体心脏上评估了它们的价值。通过结扎发自主动脉弓的两条供应身体上部的动脉来诱导脑死亡。选定心脏的保存方法是持续低温灌注20至24小时。对心脏进行活检以估计三磷酸腺苷、磷酸肌酸、乳酸和糖原，并随后进行功能测试。研究了六组猪。测试了未经历脑死亡的对照猪（A1组）的心脏、接受了4小时静脉输液和正性肌力支持的脑死亡猪（B1组）的心脏，以及另外接受了2小时激素治疗（甲状腺素2微克、皮质醇100毫克和胰岛素每小时5 - 10国际单位）的脑死亡猪（C1组）的心脏。另外3组（A2 - C2组）的处理与A1 - C1组相同，但除此之外，心脏还保存了24小时。猪脑死亡后，尽管存在无氧糖酵解，但心肌能量储备仍被消耗；这与心肌功能降低有关。向脑死亡猪施用激素导致心肌能量和糖原储备有所补充，乳酸减少，血流动力学功能相应改善。一段低温灌注保存期似乎逆转了未接受激素治疗的脑死亡动物心脏中发生的无氧代谢，但在接受激素治疗的动物中未出现这种情况，并且导致未处理动物的糖原储备得到补充。在接受激素治疗且保存的心脏中，尽管在低温灌注保存期间灌注液乳酸脱氢酶升至显著更高水平且组织乳酸水平仍很高，但功能改善且心肌能量储备增加，这一观察结果表明甲状腺素促进脑死亡动物的有氧和无氧代谢。
