Antitubulin activity of vinblastine and vincristine. Clinical implications of the radial segmentation test

The antitubulin activity of vinblastine and vincristine was compared by means of the radial segmentation test. Vinblastine was found to have antitubulin activity at least 6 times higher than that of vincristine. It is concluded that, if the differential indications for vinblastine or vincristine are balanced, it may be decisive for clinical treatment that more antitubulin activity can be administered as vinblastine than as vincristine.