No abstract

The ATP content of rat peritoneal mast cells has been studied in relation to histamine release induced by compound 48/80 and antigen-antibody (anaphylactic) reaction in vitro. When the ATP content of actively sensitized mast cells was reduced to different levels by oligomycin, a good correlation was obtained between the ATP levels and the amounts of histamine released by the anaphylactic reaction. A similar linear relation has previously been demonstrated between the ATP levels of mast cells and histamine release induced by compound 48/80. The ATP content of mast cells was also studied at different intervals after the exposure of the cells to antigen or compound 48/80. No significant change in the ATP content was observed in untreated mast cells during the short period when histamine release occurs. If, however, the mast cells were preincubated with oligomycin or 2-deoxyglucose to reduce the rate of ATP synthesis while a large part of the histamine release remained unaffected-a decrease in the ATP content could be demonstrated in close time relation to both anaphylactic and compound 48/80-induced histamine release. The observations indicate an increased utilization of ATP in mast cells during the release process.

Chakravarty, N. The mchanism of histamine release in anaphylactic reaction in guinea pig and rat. The mechanism of histamine release was studied in anaphylactic reaction in vitro in tissues from guinea pig and rat; it was compared, in rat, with histamine release induced by compound 48/80. The observations suggest that histamine release in both species is mediated by the activation of an enzyme system probably with essential sulphydryl and amino groups. Histamine release in anaphylaxis and that induced by compound 48/80 in rat appear to be mediated by the same mechanism. Some differences were observed in anaphylactic histamine release in the two species: anoxia inhibited histamine release in guinea‐pig tissue but not in rat tissue; the same was true of two triphenylmethane dyes. Despite these differences, anaphylactic histamine release in the two species seems to follow, on the whole, a common pathway.

BLOOM, G. D. and N. CHAKRAVARTY. Time course of anaphylactic histamine release and morphological changes in rat peritoneal mast cells. Acta physiol. scand. 78.410-419.Anaphylactic histamine release and concomitant morphological changes were studied in rat peritoneal mast cells. It was found that anaphylactic histamine release has a longer lag period than compound 48 /80-induced release. The time sequence of the morphological changes showed a close correlation to the histamine release. These changes were essentially characterized by vacuolation, granule alteration and granule extrusion. Some peripheral granules were extruded with only minor changes. The ultrastructural findings are consistent with a dual mechanism of histamine release-both intracellular and extracellular following granule extrusion.

Methods for microgasometry of a few hundred mast cells are described. The Cartesian ampulla diver technique is used. The sample size is determined by counting the cells within the diver. The respiration rates at 37°C, expressed in microliters per cell per hour, are 0.29 X l0 -6 without substrate and 0.47 X l0 -e with glucose.