ATP level and CO2 production of mast cells in anaphylaxis.

Abstract

The short and long-term effects of the anaphylactic reaction on energy metabolism of rat mast cells were studied. The ATP content amounted to 12.1 ± 1.1 ×10<sup>––</sup><sup>16</sup> moles per mast cell in different experiments. Following antigen challenge (horse serum 0.6%), a significant decrease of the ATP level was obtained: 16% at 30 sec and 38% at 2 min with no further change up to 10 min. The decrease was evident in the absence of metabolic substrates as well as in the presence of pyruvate. However, glucose completely counteracted the fall in ATP level. The fall in ATP content and the release of histamine were both related to the antigen concentration. No change in ATP level was observed in controls or by antigen challenge of mast cells from nonsensitized rats. Pyruvate was metabolized by oxidative metabolism in the mast cell. The CO<sub>2 </sub>production amounted to 2.2 ×10<sup>––16</sup> moles CO<sub>2</sub>/mast cell/min and was completely abolished by antimycin A. Antigen challenge of sensitized rat mast cells increased the CO<sub>2</sub> production by 30%, while no increase was observed with cells from non-sensitized rats. The increase in oxidative metabolism was not correlated to the histamine release. Thus, the same enhancement in CO<sub>2</sub> production was obtained with antigen concentrations over a great range. 2,4-Dinitrophenol mimicked the effects of antigen on the ATP level as well as on the oxidative metabolism of pyruvate. The results indicate that the antigen-antibody reaction exerts effects on the energy production in the mast cells consistent with an uncoupling of oxidative phospho-rylation.