[Allergy and histamine release (author's transl)].

Histamine is released from mastocytes and basophils polymorphonuclears. This occurs particularly in reaginic type of allergy. The different phases of the reaginic process has been studied: IgE bridgings with antigens, cell membrane activation, cytoplasmic biochemical reactions involving cyclic AMP and GMP leading to microtubules activities, contraction of microfibrils and degranulation. Calcium and magnesium contribute to the regulation of histamine release. Histamine releases could also be seen in non reaginic type of immuns allergic reactions by way of direct or indirect activation of complements, by stimulation of PAF, etc...Finally, quite a few substances could also provoke histamine release of non immunologic type (physical agents, snake and bee venoms chemical substances in micro or macromollecular forms used in therapeutics...). Their mechanisms of action are various; yet in a way, they present similaritis with immunoallergic reactions. In practice, it is often difficult to assert the allergic nature of a histaminic reaction. Immunologic evidences should be cautioniously searched before any conclusion.