Mitsui-Saito M, Ohkubo S, Obara Y, Yanagisawa T, Kobayashi J, Ohizumi Y, Nakahata N. Theonezolide A, a novel marine macrolide, induces drastic shape change in rabbit platelets by reorganization of microtubules.
Thromb Res 2002;
108:133-8. [PMID:
12590949 DOI:
10.1016/s0049-3848(02)00355-9]
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Abstract
Theonezolide A, a marine macrolide, and thrombin caused a shape change followed by an aggregation in the rabbit platelets. Theonezolide A-induced platelet shape change, estimated by a decrease in light transmission, appeared to a greater extent than thrombin-induced one. Morphological studies using an electron microscope showed that theonezolide A changed platelet shape with various numbers of long pseudopods, loosing their discoid shape. Theonezolide A-induced shape change was inhibited by a microtubule-stabilizing agent, taxol, but not by an actin-depolymerizing agent, cytochalasin B. In contrast, thrombin-induced shape change was inhibited by cytochalasin B but not by taxol. Confocal fluorescence microscopy showed that circumferential microtubule bundle disappeared in the platelets treated with theonezolide A. Theonezolide A had no direct effect on polymerization of microtubules isolated from bovine brain, indicating that it indirectly causes microtubule reorganization. These results suggest that theonezolide A induces drastic shape change through reorganization of microtubules in rabbit platelets. Thus, theonezolide A is a useful drug to examine microtubule reorganization in the cells.
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