Microtubules morphological effects

Fig. 13.8. Effect of paclitaxel on the morphology of C6 cells in culture. Cells were treated with LCM only (C,D) or paclitaxel-LCM (A,B) for 8 hours. The cells were stained with fluorescein-conjugated wheat germ agglutinin (WGA) to reveal the cell surface, and with Texas red-conjugated secondary antibody to rabbit anti-tubulin to reveal the presence of microtubules. Both channels were recorded simultaneously. Panels A and C show the presence of WGA, while B and D reveal the presence of tubulin. (Taken from ref. 532.)...

Initial reports on PTXs hepatotoxicity prompted the study of in vitro effects of these toxins on hepatocytes. There are several reports on PTX-1 and -2 in vitro cytotoxicity to hepatocytes. PTX-1 has been demonstrated to induce morphological changes and apoptosis in freshly prepared rat and sahnon hepatocytes [31,32]. PTX-1 toxic effects on primary cultures of liver cells have also been reported as disarrangement of actin and microtubule cytoskeleton [33]. Recently, in our laboratory, we found that actin cytoskeleton of primary rat hepatocytes was also altered by PTX-2 and -11 in the same way as PTX-1 but with a slightly higher potency [34]. Another primary cell type sensitive to PTXs is fresh enterocytes isolated from rabbit, in which PTX-6 induces a significant depolimeriza-tion of actin filaments [35]. 

The alterations in morphological organization of the brain resulting from hypothyroidism have been documented [10-13]. Numerous biochemical parameters are affected by altered thyroid states (for review see 14-16). Recent biochemical data on the effect of thyroid hormones on nerve cell differentiation indicate that they regulate microtubule assembly by changing the concentration and/or the activity of MAPS (tau fraction) [17]. The critical period of effectiveness of thyroid hormones in brain maturation raises a special problem. The correct organization of... 

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