Balzan S, Montali U, Biver P, Ghione S
CNR Institute of Clinical Physiology, University of Pisa, Italy.
J Nucl Biol Med (1991). 1991 Jan-Mar;35(1):38-40.
Increasing evidence indicates the existence of endogenous digitalis like factor(s) (EDLF). We recently reported on the partial purification of an EDLF from newborn (cord) blood which possesses both digoxin-like immunoreactivity and the ability to inhibit the cell membrane sodium pump measured as the inhibitory activity on erythrocyte 86Rb uptake. We here report that high affinity digoxin-binding antibodies (Fab fragments; Digibind, Burroughs Wellcome Co.) are capable of neutralizing the inhibitory activity on erythrocyte Rb uptake not only of digoxin but also of ouabain and of partially purified newborn EDLF. These results provide, to our knowledge for the first time, direct evidence that antidigitalis antibodies may cross-react with one or more circulating substances which share antigenic determinants with digoxin and ouabain and possess endogenous digitalis-like properties, strongly suggesting that these antibodies may be useful tools both for the assay of EDLF and for the study of its biological effects.
越来越多的证据表明内源性类洋地黄因子（EDLF）的存在。我们最近报道了从新生儿（脐带）血中部分纯化出一种EDLF，它具有地高辛样免疫反应性以及抑制细胞膜钠泵的能力，这种能力通过对红细胞86Rb摄取的抑制活性来衡量。我们在此报告，高亲和力地高辛结合抗体（Fab片段；Digibind，Burroughs Wellcome公司）不仅能够中和地高辛对红细胞Rb摄取的抑制活性，还能中和哇巴因以及部分纯化的新生儿EDLF的抑制活性。据我们所知，这些结果首次提供了直接证据，表明抗洋地黄抗体可能与一种或多种循环物质发生交叉反应，这些循环物质与地高辛和哇巴因具有共同的抗原决定簇，并具有内源性类洋地黄特性，这强烈表明这些抗体可能是用于检测EDLF及其生物学效应研究的有用工具。
