Erythrocytes with T-state-stabilized hemoglobin as a therapeutic tool for postischemic liver dysfunction
Erythrocytes with T-state-stabilized hemoglobin as a therapeutic tool for postischemic liver dysfunction
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DOI：
10.1089/ars.2006.8.1847
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发表时间：
2006-09-01
影响因子：
6.6
通讯作者：
Suematsu, Makoto
中科院分区：
文献类型：
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作者：
Suganuma, Kazuhiro;Tsukada, Kosuke;Suematsu, Makoto
本研究旨在研究红细胞中血红蛋白的T状态稳定是否可以保护缺血后器官损伤。制备含有三种不同状态的Hb变构的人红细胞：对照Hb（hRBC）、在R状态下用6-配位的假体血红素稳定的CO-Hb（CO-hRBC）和在T状态下稳定的α-NO-脱氧Hb（α-NO-hRBC）。为了制备α-NO-红细胞，脱氧红细胞用FK 409处理，FK 409是一种不含巯基的NO供体，其浓度为Hb的一半;该过程导致5-配位NO结合在α-亚基血红素上，通过电子自旋共振光谱法判断。使大鼠经受20分钟全身出血以将平均动脉压维持在40 mm Hg，并用一种hRBC再灌注。该缺血方案，随后用生理盐水再灌注60分钟，引起适度的代谢性酸中毒和胆汁淤积。给予hRBC或CO-hRBC显著减轻胆汁淤积并改善酸中毒。与hRBC或CO-hRBC治疗组相比，α-NO-hRBC治疗组大鼠表现出更大的代谢性酸中毒和胆汁排泄的恢复，显示出肝小叶局部氧利用的最佳结果。体内给药的α-NO-RBC的半衰期约为60分钟。这些结果表明，T-状态血红蛋白稳定NO作为一种策略，以治疗缺血后器官功能障碍。
This study aimed to examine if T-state stabilization of hemoglobin in erythrocytes could protect against postischemic organ injury. Human erythrocytes containing three different states of Hb allostery were prepared: control Hb (hRBC), CO-Hb that is stabilized under R-state with the 6-coodinated prosthetic heme (CO-hRBC), and alpha-NO-deoxyHb stabilized under T-state (alpha-NO-hRBC). To prepare alpha-NO-RBC, deoxygenated RBC was treated with FK409, a thiol-free NO donor, at its half molar concentration to that of Hb; this procedure resulted in the 5-coordinated NO binding on the alpha-subunit heme, as judged by electron spin resonance spectrometry. Rats were subject to 20 min systemic hemorrhage to maintain mean arterial pressure at 40 mm Hg, and reperfused with one of hRBCs. This protocol for ischemia, followed by 60 min reperfusion with physiological saline, caused modest metabolic acidosis and cholestasis. Administration of hRBC or CO-hRBC significantly attenuated cholestasis and improved acidosis. Rats treated with alpha-NO-hRBC exhibited greater recovery of metabolic acidosis and bile excretion than those treated with hRBC or CO-hRBC, displaying the best outcome of local oxygen utilization in hepatic lobules. Half-life time of alpha-NO-RBC administered in vivo was approximately 60 min. These results suggest that T-state Hb stabilization by NO serves as a stratagem to treat postischemic organ dysfunction.