B. Emadikhiav et Fl. Pearce, SOME STUDIES ON THE EFFECTS OF ALPHA-CHYMOTRYPSIN ON MAST-CELLS FROM THE RAT AND OTHER SPECIES, European journal of pharmacology, 295(2-3), 1996, pp. 243-252
We have examined the effect of alpha-chymotrypsin on isolated mast cel
ls from different sources. The enzyme induced a dose-dependent secreti
on of histamine from purified and non-purified populations of rat peri
toneal mast cells. The release was non-cytotoxic and was inhibited by
metabolic blockers and extremes of temperature. The process was relati
vely slow, being essentially complete within 20 min, and was unaffecte
d by phosphatidylserine. A substantial component of the secretion pers
isted in the absence of extracellular Ca2+. The release was suppressed
by extremes of pH and a variety of anti-allergic compounds and serine
esterase inhibitors. In addition to the secretion of preformed mediat
ors, alpha-chymotrypsin also induced the metabolism of arachidonic aci
d, resulting in the release of prostaglandin D-2 in a dose-related man
ner from purified rat peritoneal mast cells. alpha-Chymotrypsin exhibi
ted a marked tissue and species selectivity in its action and tissue m
ast cells of the rat, guinea pig and human were generally resistant to
the enzyme except at cytotoxic concentrations. On the basis of these
results, the possible role of endogenous serine esterases in mast cell
activation is discussed.