Histamine release from human leukocytes: studies with deuterium oxide, colchicine, and cytochalasin B

Abstract

A B S T R A C T Agents known to interact with either microtubules or microfilaments influenced the antigen-induced release of histamine from the leukocytes of allergic individuals. Deuterium oxide (D20) which stabilizes microtubules and thereby favors their formation enhanced histamine release markedly. Concentrations as low as 5% increased antigen-induced release somnewhat while concentrations as high as 75% had no effect on release in the absence of antigen. Enhancement occurred over a wide range of antigen concentrations and was also seen when release was initiated by antibody to IgE or IgG. When the release process was divided into two stages a D20 activity could be demonstrated only in the second stage. However, when D20 was present in the first stage together with agents which raise cyclic AMP levels and thereby inhibit release it partially reversed this inhibition. Colchicine, demecolcine, and vinblastine, compounds known to disaggregate microtubules, i.e., have an effect opposite to that of D20, inhibited the release of histamine and counteracted the effects of D20. The inhibitory action of colchicine was greater if cells were treated with colchicine before rather than after activation with antigen. Cytochalasin B, a compound which causes the disappearance of microfilaments, had variable effects on histamine release. The most frequently seen response was slight enhancement. Neither D20 nor cytochalasin B altered cyclic AMP levels in leukocytes. These observations support and strengthen the view that an intact and functioning microtubule system is directly important for the secretion of histamine from leukocytes and suggest that microfilaments might have multiple indirect effects.

Human Lung Tissue and Anaphylaxis

“…The data reported herein confirms the requirement for functional microtubules in mediator release (6)(7)(8)(9) as indicated by the inhibitory action of colchicine under defined conditions. Furthermore, data are presented which suggests that cyclic AMP and GMP exert their modulating effects on the secretion of mediators from human lung by influencing the state of microtubular assembly.…”

“…Although colchicine has been reported to impede secretory reactions in several tissues (3)(4)(5)(6)(7)(8)(9), it was initially difficult to reproduce these findings. Incubation of sensitized lung fragments under varied conditions in eight initial experiments with colchicine (0.0001-1 mM), and one experiment with vinblastine (0.01 mM) and podophylline (1 ,ug/ml) resulted in minimal suppression of the immunologic release ofhistamine and no inhibition of SRS-A release (Table I).…”

“…As disassembly of polymerized microtubules is known to be favored by cold temperatures (32) and was observed to augment the inhibition of histamine from human leukocytes by colchicine (7,8), the effects of cold temperature on colchicine inhibition of mediator release from human lung tissue was examined ( Fig. 1).…”

“…These biochemical events translate the immunologic signal at the surface of the lung mast cell to the intracellular process of moving the mediator containing secretory granules toward the cell surface where sequential exocytosis (2) occurs. Functioning microtubules have been shown to be necessary for many secretory processes (3)(4)(5) including the nonimmunologic release of histamine from human peripheral leukocytes (7,8) and human lung tissue (9). It seemed possible, therefore, that a portion of the partially delineated biochemical sequence of events involved in the immunologic release process might relate to the assembly and function of microtubules.…”

Two Regions of Down-Regulation in the IgE-Mediated Signaling Pathway in Human Basophils

“…For example, there appears to be a down-regulatory mechanism that involves the cytoskeleton and its regulation of lipid raft constituents (9,10). Agents that inhibit cytoskeletal formation markedly enhance secretion in RBL cells and have the same functional effect in basophils (11). Recent studies in murine mast cells suggest that Src homology 2-containing 5Ј-inositol phosphatase (SHIP) is a critical down-regulator of ongoing secretion whose absence leads to hypersecretion (12), and a similar finding may apply to human basophils (13,14).…”