Influence of hyposensitization of ATP level and CO2 production of mast cells in anaphylaxis.

Anaphylaxis in a glucose-free medium containing pyruvate caused a release of histamine and a significant decrease in the ATP level of rat mast cells. The fall was maximal after 10 min and it was found to reverse after 22 min. Glucose completely counteracted the ATP fall without changing the anaphylactic histamine release. Furthermore, the oxidative metabolism of exogenous pyruvate to CO2 was stimulated in the mast cell. A high level of protection of mast cells to antigen challenge was obtained following hyposensitization and only a small amount of the intracellular histamine was released in contrast to non-hyposensitized cells. Hyposensitization counteracted the ATP fall by antigen challenge but the increase in oxidative metabolism remained unchanged. The results indicate that hyposensitization exerts effects in the mast cell consistent with a reduced ATP utilization or with a reduced uncoupling of oxidative phosphorylation. The mechanism of the hyposensitization must be due to inhibition of one or more of the cellular steps leading to histamine release and subsequent morphological changes of the cell or to uncoupling of oxidative phosphorylation.