Respiration-enhancing effect of tuberculin on splenic cells of hypersensitive guinea pigs.

Oxygen utilization in splenic cells of normal and BCG-sensitized guinea pigs was measured in a Warburg respirometer in the absence and in the presence of Old Tuberculin (OT). In the absence of OT, normal and sensitive cells respired at the same rate; in the presence of OT, normal cell respiration remained unchanged, whereas the respiration of sensitive cells increased significantly. This enhancement of oxygen utilization in sensitive cells was induced with OT but not with Purified Protein Derivative and it was most pronounced during the first hour of the interaction between the cells and the antigen. When normal splenic cells were treated with an extract of hypersensitive cells, their respiration was enhanced in the presence of OT. Oxygen utilization in cells of desensitized animals did not differ from that in cells of normal animals. The absence of reactivity to OT in splenic cells and in the skin of desensitized guinea pigs suggested that both phenomena are expressions of antigen-induced biological changes in cells of animals with delayed hypersensitivity.