Histamine Releasers and Rat Mast Cells

Abstract

The release of histamine from rat tissues rich in mast cells, induced by antigen, concanavalin A, dextran, compound 48/80, A 23187, phosphatidic acid and chlortetracycline, has been compared with that from isolated peritoneal mast cells of rats. Whereas most of the agents were more active than dextran in in vitro experiments, the reverse was found when they were injected intradermally into the skin, or subcutaneously into the paws. In fact, A 23187 and chlortetracycline (both calcium ionophores), as well as phosphatidic acid (another non-cytotoxic releaser), failed to release significant amounts of histamine when injected into the animal. Thus, the experimental conditions in which comparisons of the activities of histamine releasers are made should always be stated.

Antagonistic Analogs of Luteinizing Hormone-Releasing Hormone Are Mast Cell Secretagogues

“…It has previously been reported that histamine-releasing activity in vitro does not always correspond to activity in the whole animal [20], This was true of this series of experiments in that all antagonists released histamine in vitro but only I and III caused increased levels in vivo. In addition, there was no apparent correlation in the rank order of potencies with regard to histamine release in vitro, the skin test reactivity in vivo, and the occurrence of the edematous response.…”

“…Histamine is a mediator of the edematous reactions induced in rats by dextran and 48/80 [20,21] and skin lesions in duced by intradermal injection of mast cell secretagogues [22,23]. However, serotonin is also involved in these reactions [21] and can be preferentially released from mast cells [24], Although all antagonists caused mast cell histamine release in vitro, and while an tagonists I and III did so in vivo, it may be that the antagonists release other mast cell mediators which are important in these reactions.…”

Effect of Lodoxamide on in vitro and in vivo Conjunctival Immediate Hypersensitivity Responses in Rats

“…It has been reported that Naaxia prevents an immune complex-mediated inflammatory reaction [15]; however, the relevance of this activity to acute classical type-I immediate hypersensitivity reactions remains to be determined. Secchi et al [16] reported that Naaxia inhibits histamine release from guinea-pig choroidal tissue chal lenged with compound 48/80, a nonspecific, IgE-independent mast cell secretagoguc capable of causing hista mine release in the absence of calcium and glucose [17].…”

Effect of fruits of Opuntia elatior Mill on mast cell degranulation

“…[ 17 ] On the other hand, anaphylactic release requires the presence of calcium in the extracellular medium, which moves onto the cell via calcium gates in the membranes. [ 15 18 ] A significant protection of rat peritoneal mast cells from disruption by antigen and compound 48/80 by fruit juice of O. elatior Mill. points toward its ability to interfere the release and/or synthesis of mediators of inflammation, indicating its mast cell stabilizing activity.…”