Influence of substances affecting cell sulfhydryl/disulfide status on adherence of human monocytes.

An in-vitro model is described for investigating the adherence of human monocytes. Mononuclear cells (MNC) isolated from peripheral blood were incubated in plastic multiwell cell culture plates. The adherence of monocytes was quantified on the basis of their DNA content. The cell adherence proceeds rapidly; after 30 min of incubation about 85% of maximum adherent cells were attached to the plastic surface. On testing the effects of various sulfhydryl-affecting substances on monocyte adherence we found that the thiol-oxidizing compound diamide (0.1-1 mmol/l) inhibited the adherence by about 60%. Incubation with an extract of the plant feverfew, which contains materials that neutralize cellular sulfhydryl groups, also diminished monocyte adherence. The soluble thiol 2-mercaptopropionylglycine, in a concentration range of 0.5 to 10 mmol/l, had no effect on adherence in this system. The results suggest that cellular sulfhydryl groups play an important role in the adherence of monocytes.