Effect of unlabeled indium oxine and indium tropolone on the function of isolated human lymphocytes.

The purpose of this study was to compare the effect of indium oxine and indium-tropolone complexes (nonradiolabeled) on the function of isolated human lymphocytes. peripheral lymphocytes were obtained from 15 normal volunteers and incubated with indium oxine or indium tropolone according to the standard techniques currently used when cells are radiolabeled for subsequent in vivo studies. The phytohemagglutinin-induced (PHA) lymphocyte transformation and a more specific lymphocyte functional test (the mixed lymphocyte reaction) were performed following incubation with the indium complexes. The results indicate that PHA transformation is not affected by either indium oxine or indium tropolone, whereas both chelates reduced the mixed lymphocyte reaction. This suggests that these substances have a selective toxic effect only on a functionally distinct lymphocyte subset (i.e., the cytotoxic T cells) and indicates that there is no significant difference between the two indium chelates in terms of their effect on lymphocyte function.