Complement-mediated release of histamine from human basophils. III. Possible regulatory role of microtubules and microfilaments

The release of histamine by normal human leukocytes (basophils) following in vitro challenge with activated complement (zymosan-treated serum) was previously reported. In this study, the effects of various pharmacologic agents on this release mechanism were compared with allergen-induced release of histamine. Colchicine and vinblastine antagonize the polymerization of tubulin to form microtubules, and both agents inhibited complement- and allergen-mediated release of histamine. The dose-response effects of these drugs were quite similar for the two release mechanisms. Deuterium oxide, an agent which stabilizes microtubules, enhanced both complement- and allergen-triggered release of histamine from basophils. Finally, treatment with cytochalasin B, a fungal product known to interfere with microfilament formation, resulted in enhanced release of histamine from complement-treated basophils but no significant change in the percentage of histamine released from allergen-treated basophils. These findings suggest that microtubules and/or microfilaments are involved in complement-induced secretion of histamine by human basophils.