CALCIUM-DEPENDENT HISTAMINE RELEASE WITH DEGRANULATION FROM ISOLATED RAT MAST CELLS BY ADENOSINE 5'-TRIPHOSPHATE

Abstract

It has generally been recognized that histamine release from mast cells induced by antigen-antibody reaction, as well as by certain basic compounds, is dependent upon the cellular energy generating processes since these reactions are inhibited by anoxic conditions and by metabolic inhibitors which uncouples oxidative phosphorylation or block respiratory enzymes (1-7). A preliminary study was attempted in order to see whether adenosine 5'-triphosphatase (ATPase) is really activated in association with the release of histamine. However, it was unexpectedly found, at the beginning of such a work, that adenosine 5'-triphosphate (ATP) itself caused a marked histamine release and this was accompanied with conspicuous morphological changes characterized by the degranulation of mast cells when the medium contained calcium ions.
Keller (8), and Diamant and Krüger (9, 10) have reported that histamine release was elicited by ATP present extracellularly, but the latter authors did not observed the occurrence of degranulation concomitant with the release of histamine even in the calciumcontaining medium, unlike the present observation, although they found some morphological changes in msat cells discernible from those induced by a histamine liberator, compound 48/80.
The present paper describes observations on the morphological changes and on the release of histamine in isolated rat peritoneal mast cells under the effect of exogenous ATP, with special reference to the combined effect of calcium ions.
A preliminary report on these findings has been published earlier (11).