Anti-tubulin immunofluorescence studies of recovery from vinblastine cytotoxicity in Chinese hamster cells.
Antitubulin immunofluorescent staining was used to examine the relationship among crystal formation, mitotic arrest, and recovery potential in vinblastine-treated Chinese hamster cells. Although vinblastine caused a mitotic block at concentrations as low as 5 x 10(-9) M, it induced tubulin crystal formation only at concentrations higher than 10(-6) M. At these higher concentrations, cells took 48-72 h to recover after return to normal medium. This extended period of time was apparently needed for breakdown of the crystals and regeneration of normal cytoplasmic microtubules. At concentrations less than 10(-6) M, although the mitotic block was still effective, no crystals were present. Possibly because of this lack of crystal formation, the cells recovered rapidly, generating cytoplasmic microtubules within 30 min, and beginning to undergo mitosis within 60 min. These findings tend to support biochemical evidence that tubulin binds to vinblastine at two types of binding site: a high affinity, low capacity site, responsible for tubulin disaggregation; and a low affinity site, responsible for protofilament splaying.
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D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D003460:Crystallization; D005347:Fibroblasts / Q000187:drug effects*; D005455:Fluorescent Antibody Technique; D007106:Immune Sera; D008938:Mitosis / Q000187:drug effects; D013194:Staining and Labeling; D014404:Tubulin / Q000032:analysis* / Q000276:immunology; D014747:Vinblastine / Q000633:toxicity*
D007106:Immune Sera; D014404:Tubulin; D014747:Vinblastine