Abstract
Producion of superoxide anion, probably by the action of NADPH oxidase in the cell membrane, was markedly stimulated in guinea pig polymorphonuclear leukocytes by the treatment with membrane-perturbing agents such as cytochalasin D, phorbol myristate acetate, concanavalin A, etc. Anti-microtubular agents, vinblastine and colchicine, further increased the cytochlasin D-or phorbol myristate acetate-stimulated superoxide anion production at a certain concentration range. From the results of experiments to change the intracellular situation, it was assumed that the effect of the anti-microtubular agents was due to the alteration of the state of microtubules around the cell membrane, which might be involved in the regulation of the activity of membrane enzymes. The anti-microtubular agents, however, had little effect on the concanavalin A-stimulated superoxide anion production. The results suggested that the involvement of microtubules in the effect of membrane-perturbing agents was not common but depended on the site of the action of each of the membrane-perturbing agents.
