The effects of vinblastine on the cell structure and activity in the rat incisor enamel organ during the secretory stage in vivo as shown by radioautography using 3H-proline, 3H-serine and 3H-fucose.
Four hours after injection of vinblastine sulphate (VBL) the cells of the enamel organ of the rat incisor showed: 1) loss of polarity in the tall secretory ameloblasts--secretory granules, which were lacking in the Tomes processes accumulated in the supranuclear area; condensing vacuoles also accumulated near dictyosomes; enlarged intercellular spaces without disruption of intercellular junctions; lysosomal structures and autophagic vacuoles. 2) an increase of lysosome-like structures in the outer enamel epithelium, the stellate reticulum and the stratum intermedium. 3) a severe reduction in number of free ribosomes in the stratum intermedium as well as an increase in size of the Golgi complex: numerous electron lucent vesicles appeared. These findings as well as radioautographic data demonstrated 1) the impairment of secretory activity of ameloblasts. 2) the restriction of permeability in the enamel organ suggesting strong interaction between VBL and the membranes.
D000565:Ameloblasts / Q000187:drug effects; D000818:Animals; D001345:Autoradiography; D004658:Enamel Organ / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005643:Fucose; D009940:Organoids / Q000648:ultrastructure; D011392:Proline; D051381:Rats; D011919:Rats, Inbred Strains; D012694:Serine; D014083:Tooth Germ / Q000187:drug effects*; D014316:Tritium; D014747:Vinblastine / Q000494:pharmacology*
D014316:Tritium; D005643:Fucose; D012694:Serine; D014747:Vinblastine; D011392:Proline