Altura B T, Altura B M
Department of Physiology, State University of New York, Health Science Center, Brooklyn.
Magnes Trace Elem. 1991;10(2-4):90-8.
A novel ion selective electrode (ISE) for ionized magnesium (IMg2+) in whole blood (WB), plasma (PL), and serum (S) has been designed. We have undertaken a number of studies, experimental and clinical, to characterize and examine the linearity, precision, specificity, accuracy, and utility of this new ISE for IMg2+ in WB, S, and PL of normal human subjects, diseased subjects and animals. Using aqueous solutions, mean IMg2+ values are within 94.6-99.2% of their targets. The linearity of the ISE (0.1-3.0 mM) in aqueous solutions, and human PL and S ranges between 92.0 and 99.3%. The ISE is highly selective for IMg2+, yielding measurements in less than 2 min, and exhibiting no or negligible effects from pathophysiologic concentrations of Ca2+, Na+, K+, H+ or NH4+. Likewise such concentrations of heavy metals (e.g., Fe3+, Cu2+, Zn2+, Cd2+, Hg2+ and Pb2+) in aqueous solution and serum do not interfere with ISE measurements for IMg2+. Ligand binding studies in aqueous solution indicate that pathophysiologic concentrations of different anions (e.g., heparin, bicarbonate, phosphate, acetate, sulfate and lactate) bind to Mg2+ with varying intensities, effectively reducing its concentration in solutions. IMg2+ measurements on WB, PL, and S for a given person's samples are virtually identical. Typically, IMg2+ is 71% of total Mg (TMg) but varies from subject to subject. The IMg2+ is held within a narrow range (0.53-0.67 mM) in normal, healthy controls. Studies on diseased human subjects (i.e., cardiac cases, cardiopulmonary bypass, abnormal pregnancy, renal transplant recipients, diabetics, asthmatics, etc.) indicate that IMg2+ levels often exhibit significant alterations from normality, despite no change in TMg.(ABSTRACT TRUNCATED AT 250 WORDS)
已设计出一种用于检测全血（WB）、血浆（PL）和血清（S）中离子化镁（IMg2+）的新型离子选择性电极（ISE）。我们进行了多项实验研究和临床研究，以表征和检验这种新型ISE在正常人类受试者、患病受试者和动物的WB、S和PL中检测IMg2+的线性、精密度、特异性、准确性和实用性。在水溶液中，IMg2+的平均测量值在其目标值的94.6%至99.2%范围内。ISE在水溶液、人体PL和S中的线性范围（0.1 - 3.0 mM）在92.0%至99.3%之间。该ISE对IMg2+具有高度选择性，测量时间不到2分钟，并且不受病理生理浓度的Ca2+、Na+、K+、H+或NH4+影响或影响可忽略不计。同样，水溶液和血清中此类浓度的重金属（如Fe3+、Cu2+、Zn2+、Cd2+、Hg2+和Pb2+）也不会干扰IMg2+的ISE测量。水溶液中的配体结合研究表明，不同阴离子（如肝素、碳酸氢盐、磷酸盐、乙酸盐、硫酸盐和乳酸盐）的病理生理浓度以不同强度与Mg2+结合，有效降低了其在溶液中的浓度。对同一个人样本的WB、PL和S进行的IMg2+测量几乎相同。通常，IMg2+占总镁（TMg）的71%，但个体之间存在差异。在正常健康对照中，IMg2+保持在狭窄范围内（0.53 - 0.67 mM）。对患病人类受试者（即心脏病患者、体外循环患者、异常妊娠患者、肾移植受者糖尿病患者、哮喘患者等）的研究表明，尽管TMg没有变化，但IMg2+水平通常与正常情况相比有显著改变。（摘要截选至250字）
