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Activated human basophils contain histamine in cytoplasmic vesicles
A M Dvorak1, E S Morgan, L M Lichtenstein
1Department of Pathology, Beth Israel Hospital, Boston, Mass 02215.
International Archives of Allergy and Immunology
|September 1, 1994
Summary
Human basophils release histamine slowly via piecemeal degranulation, unlike explosive anaphylactic degranulation. This study identifies cytoplasmic vesicles as key in histamine secretion during piecemeal degranulation in contact allergy.
Area of Science:
- Immunology
- Cell Biology
- Allergy Research
Background:
- Human basophils exhibit piecemeal degranulation, a slow secretory process distinct from rapid anaphylactic degranulation.
- Histamine, a key proinflammatory mediator, is stored in basophil granules.
Purpose of the Study:
- To investigate the mechanism of histamine release during piecemeal degranulation in human basophils.
- To identify the cellular components involved in histamine secretion in contact allergy.
Main Methods:
- Utilized an ultrastructural enzyme-affinity method with diamine oxidase coupled to gold for histamine localization.
- Stimulated human basophils with FMLP (N-formyl-methionyl-leucyl-phenylalanine) to induce histamine release.
- Examined basophils at 20 seconds post-stimulation using electron microscopy.
Main Results:
- Gold labeling confirmed the presence of histamine in cytoplasmic vesicles and granules of stimulated human basophils.
- Observed evidence of histamine within cytoplasmic vesicles, suggesting their role in secretion.
- Piecemeal degranulation morphology was associated with these histamine-containing vesicles.
Conclusions:
- Cytoplasmic vesicles are implicated as a crucial component in the piecemeal degranulation pathway for histamine secretion from human basophils.
- Findings provide insight into the cellular mechanisms underlying histamine release in conditions like contact allergy.
- This research highlights the distinct secretory processes of basophils and their mediators.