Barnard M L, Muller-Eberhard U, Turrens J F
Department of Biomedical Sciences, University of South Alabama, Mobile 36688.
Biochem Biophys Res Commun. 1993 Apr 15;192(1):82-7. doi: 10.1006/bbrc.1993.1384.
Tert-butyl hydroperoxide (t-BOOH)-dependent chemiluminescence of perfused rat lungs increased by almost 500% upon addition of heme (from 297 +/- 28% to 1204 +/- 125% of control, p < 0.01 vs no heme). Preincubation with hemopexin significantly decreased the heme-stimulated chemiluminescence to 779 +/- 155% of control (p < 0.01) When hemopexin was replaced with rat albumin heme-stimulated chemiluminescence decreased to 1007 +/- 104% (not significantly different from results with heme alone). In vitro studies showed that hemopexin did not decrease chemiluminescence from bovine serum albumin oxidation (493 +/- 94% compared to 292 +/- 81% of control in the absence of hemopexin) and that the heme-hemopexin mixture also emitted light when exposed to t-BOOH (264 +/- 66% of control). These results suggest that hemopexin specifically inhibits some of the oxidative reactions catalyzed by free heme and may have a protect tissue oxidation in conditions in which heme release occurs (i.e., stroke).
灌注大鼠肺脏的叔丁基过氧化氢（t-BOOH）依赖性化学发光在添加血红素后增加了近500%（从对照组的297±28%增至1204±125%，与未添加血红素相比，p<0.01）。与血红素结合蛋白预孵育可使血红素刺激的化学发光显著降低至对照组的779±155%（p<0.01）。当用大鼠白蛋白替代血红素结合蛋白时，血红素刺激的化学发光降至1007±104%（与单独使用血红素的结果无显著差异）。体外研究表明，血红素结合蛋白不会降低牛血清白蛋白氧化产生的化学发光（与无血红素结合蛋白时对照组的292±81%相比为493±94%），并且血红素-血红素结合蛋白混合物在暴露于t-BOOH时也会发光（为对照组的264±66%）。这些结果表明，血红素结合蛋白特异性抑制游离血红素催化的某些氧化反应，并且在发生血红素释放的情况下（即中风）可能具有保护组织氧化的作用。
