Serial changes in myocardial beta-adrenergic receptor after experimental brain death in dogs.
Serial changes in myocardial beta-adrenergic receptor after experimental brain death in dogs.
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狗实验性脑死亡后心肌β-肾上腺素能受体的连续变化。
DOI：
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发表时间：
1992
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影响因子：
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通讯作者：
H. Matsuda
中科院分区：
文献类型：
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作者：
N. Sakagoshi;R. Shirakura;S. Nakano;K. Taniguchi;Y. Miyamoto;H. Matsuda
早期供心衰竭是心脏移植中的严重问题之一。这种心力衰竭可能与心脏植入前脑死亡时的心肌变化有关。事实上，在脑死亡患者中，维持血流动力学的儿茶酚胺需求量逐渐增加并不少见。这可能与心肌β-肾上腺素能受体系统的改变有关。本实验研究了犬高颅压脑死亡后心肌β-肾上腺素能受体的变化。为维持脑死亡后平均动脉压在60 mm Hg以上，A组给予大剂量晶体输注(A组)，B组给予0.4~1.3 mg/kg/min肾上腺素输注。分别于脑死亡后3h(A-3H组或B-3H组，n=5)和6h(A-6H组或B-6H组，n=5)测定血肾上腺素水平和心肌β-肾上腺素能受体(与[125I]碘氰基吲哚结合的受体数目和亲和力)。血肾上腺素水平在A-6H组降低，B-3H组和B-6H组升高。各组间β-肾上腺素能受体亲和力无差异。B-6H组β-肾上腺素能受体数量减少。脑死亡后维持血流动力学的6小时内，肾上腺素组心肌β受体密度降低，而结晶组心肌β受体密度无变化。我们的数据表明，脑死亡供者用于维持血流动力学的大剂量儿茶酚胺可能会抑制心肌β-肾上腺素能受体。
Early donor heart failure is one of the serious problems in heart transplantation. This heart failure may be related to myocardial change during brain death before implantation of the heart. Actually, a gradual increment in catecholamine requirement to maintain hemodynamics is not infrequently seen in patients with brain death. This may presumably be related to alterations in the myocardial beta-adrenergic receptor system. In this experimental study, we investigated the changes in myocardial beta-adrenergic receptors after brain death induced by intracranial hypertension in dogs. To maintain the mean arterial pressure higher than 60 mm Hg after brain death, massive crystalloid infusion (group A) or 0.4 to 1.3 micrograms/kg/min of adrenaline infusion (group B) was applied. Blood adrenaline levels and myocardial beta-adrenergic receptor (receptor number and affinity with [125I]iodocyanopindolol binding) were measured at 3 hours (group A-3H or group B-3H, n = 5, respectively) and 6 hours (group A-6H or group B-6H, n = 5, respectively) after brain death. Blood adrenaline levels reduced in group A-6H and elevated in group B-3H and group B-6H. Beta-adrenergic receptor affinity was not different among each group. Beta-adrenergic receptor number decreased in group B-6H. Myocardial beta-adrenergic receptor density decreased in the adrenaline group during 6 hours of hemodynamic maintenance after brain death, whereas myocardial beta-adrenergic receptors did not change in the crystalloid group. Our data suggest that the large doses of catecholamines used to maintain hemodynamics in donors with brain death may depress myocardial beta-adrenergic receptors.