Finnie M, Fullerton G D, Cameron I L
Department of Radiology, University of Texas Health Science Center, San Antonio 78284.
Magn Reson Imaging. 1986;4(4):305-10. doi: 10.1016/0730-725x(86)91040-4.
The contribution of hemolysis, proteolysis and the paramagnetic effect of iron on the proton spin-lattice (T1) relaxation time in blood was examined. Hemolysis induced by sonication resulted in a significant (10%) increase in the T1 relaxation time of whole blood. Proteolysis in both sonicated and unsonicated whole blood samples eventually yielded T1 values which correlated well with the relaxation times of free iron in plasma or water at concentrations comparable to the concentration of iron in whole blood. It is concluded that proteolysis allows the iron atom to express its paramagnetic effect on water relaxation by gradually destroying the hydrophobic nature of the pocket in which iron resides on the hemoglobin molecule. The contribution of various blood components to the T1 relaxation of whole blood was also studied. The T1 values for packed erythrocytes, intact whole blood, sonicated whole blood, plasma and serum proved to be significantly different from each other. Serum was found to have a significantly (12%) longer T1 relaxation time than plasma. Packed clotted blood in vitro showed no change in the T1 time for at least 13 days while packed erythrocytes showed a shortening of T1 time after 6-8 days.
研究了溶血、蛋白水解以及铁的顺磁效应对血液中质子自旋晶格（T1）弛豫时间的影响。超声处理诱导的溶血导致全血的T1弛豫时间显著增加（10%）。超声处理和未超声处理的全血样本中的蛋白水解最终产生的T1值，与血浆或水中游离铁在与全血中铁浓度相当的浓度下的弛豫时间具有良好的相关性。得出的结论是，蛋白水解通过逐渐破坏铁在血红蛋白分子上所处口袋的疏水性，使铁原子能够对水的弛豫表现出顺磁效应。还研究了各种血液成分对全血T1弛豫的贡献。结果证明，浓缩红细胞、完整全血、超声处理全血、血浆和血清的T1值彼此之间存在显著差异。发现血清的T1弛豫时间比血浆长12%。体外浓缩的凝血血液在至少13天内T1时间无变化，而浓缩红细胞在6 - 8天后T1时间缩短。
