Baumal R, Broder I
Clin Exp Immunol. 1968 Jul;3(6):525-36.
Soluble antigen–antibody complexes (SC) have in the past been shown to activate histamine release from the isolated perfused guinea-pig lung. In the current studies this system has been used as a biological assay for the detection of SC present in serum. However, serum contained an inhibitor substance which suppressed the histamine-releasing activity of SC. The presence of this inhibitor resulted in the bioassay being relatively insensitive, with a capacity to detect SC present in serum at a minimum concentration of approximately 32–128 μg antibody N/ml. By fractionating the serum on Sephadex G-200, it was possible to separate the inhibitor (middle fraction) from the SC (excluded fraction), resulting in a capacity to detect SC which were initially present in serum at concentrations of approximately 3·2–8 γg antibody N /ml. There was a more efficient recovery of complexes in the Sephadex excluded fraction obtained from SC containing intermediate and late response antibody than from SC containing early response antibody. Most of the free antigen present in the starting preparations of SC became separated from the complexes during passage through Sephadex G-200; however, the amount of antigen recovered with antibody in the Sephadex excluded fraction was in excess of that required for equivalence. It was concluded that the isolated perfused guinea-pig lung could be used as a sensitive bioassay for the detection of SC present in the Sephadex excluded fraction of serum.
可溶性抗原-抗体复合物（SC）过去已被证明可激活从离体灌注豚鼠肺中释放组胺。在当前的研究中，该系统已被用作检测血清中存在的SC的生物学测定方法。然而，血清中含有一种抑制物质，它抑制了SC的组胺释放活性。这种抑制剂的存在导致生物测定相对不敏感，其检测血清中存在的SC的能力最低浓度约为32-128μg抗体N/ml。通过在葡聚糖G-200上对血清进行分级分离，可以将抑制剂（中间级分）与SC（排阻级分）分离，从而能够检测最初存在于血清中浓度约为3.2-8μg抗体N/ml的SC。从含有中期和晚期反应抗体的SC获得的葡聚糖排阻级分中复合物的回收率比从含有早期反应抗体的SC中更高。在通过葡聚糖G-200的过程中，SC起始制剂中存在的大多数游离抗原与复合物分离；然而，在葡聚糖排阻级分中与抗体一起回收的抗原量超过了当量所需的量。得出的结论是，离体灌注豚鼠肺可作为一种灵敏的生物测定方法，用于检测血清葡聚糖排阻级分中存在的SC。
