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Synergistic effects of calcium‐mobilizing agents and adenosine on histamine release from rat peritoneal mast cells
Author(s) -
Lohse Martin J.,
Maurer Klaus,
Klotz KarlNorbert,
Schwabe Ulrich
Publication year - 1989
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1989.tb12689.x
Subject(s) - adenosine , histamine , calcium , mast cell , chemistry , adenosine receptor , medicine , endocrinology , liberation , purinergic signalling , adenosine a1 receptor , calcium in biology , pharmacology , biology , biochemistry , receptor , immunology , in vitro , agonist
1 Adenosine and its metabolically stable analogue N‐ethyl‐carboxamidoadenosine (NECA) enhance histamine release from rat peritoneal mast cells when these are stimulated by calcium‐mobilizing agents. NECA and adenosine shift the concentration‐response curve of the calcium ionophore A23187 to lower concentrations. 2 The potencies of NECA or adenosine in enhancing A23187‐induced histamine release are dependent on the level of stimulated release in the absence of adenosine analogues. At high levels of release their potencies are up to 20 times higher than at low levels. Consequently, averaged concentration‐response curves of adenosine and NECA for enhancing histamine release are shallow. 3 The adenosine transport blocker S‐( p ‐nitrobenzyl)‐6‐thioinosine (NBTI) has no effect by itself at low levels of stimulated histamine release, but abolishes the enhancing effect of adenosine. At high levels of release, however, NBTI alone enhances the release of histamine. 4 It is concluded that adenosine and calcium reciprocally enhance the sensitivity of the secretory processes to the effects of the other agent. The levels of intracellular adenosine obtained by trapping adenosine inside stimulated mast cells are sufficient to enhance histamine release substantially, suggesting that this effect may play a physiological and pathophysiological role.