In vivo assessment of mast cell functional alteration induced by L-leucine methyl ester, using the passive cutaneous anaphylaxis technique.
We have recently reported that in vitro, mast cells were sensitive to the action of L-leucine methyl ester (Leu-OMe), a lysosomotropic compound. We now report the in vivo effect of Leu-OMe on mast cells, qualitatively assessed by using the passive cutaneous anaphylaxis (PCA) reaction. The L- but not the D-stereoisomer of Leu-OMe (25 mM) injected together with Dactylis glomerata, pollen-specific, IgE-containing serum inhibited the PCA reaction in rat skin triggered by a subsequent challenge with the corresponding allergen. When specific IgE antibodies were injected in the rat skin 3 days after the L-Leu-OMe, subsequent challenge with the antigen displayed a recovery of the PCA reaction. Thus, an in vivo L-Leu-OMe treatment, at a concentration which did not lead to any macroscopic tissue injury, elicited either an alteration of mast cell mediator release or an inhibition of allergen-induced vasoactive mediator release through a functional deactivation and/or a depletion of mast cells.
Oskéritzian
C
C
Unité d'Immuno-Allergie, Institut Pasteur, Paris, France.
Peronet
R
R
Prouvost-Danon
A
A
David
B
B
D000485:Allergens / Q000008:administration & dosage; D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D007073:Immunoglobulin E / Q000276:immunology; D007271:Injections, Intradermal; D007930:Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008407:Mast Cells / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D051379:Mice; D010323:Passive Cutaneous Anaphylaxis / Q000502:physiology; D011058:Pollen / Q000276:immunology; D051381:Rats; D013237:Stereoisomerism
D000485:Allergens; D000888:Antibodies, Anti-Idiotypic; C030365:leucine methyl ester; D007073:Immunoglobulin E; D007930:Leucine