title: Effects of colchicine on the ultrastructure of mouse taste buds.
abstract: Effect of colchicine on the ultrastructure of taste bud cells was studied in the mouse. In untreated mice microtubules were abundant throughout the entire cytoplasm of type-III cells, but only in the apical cytoplasm of type-I cells. After 2 h of colchicine treatment, no microtubules were observed in any taste bud cells; dense secretory granules in the apical cytoplasm of type-I cells mostly disappeared, and instead, numerous phagosomes appeared. It is suggested that colchicine causes an interruption of the transport of the secretory granules in type-I cells from the Golgi apparatus to the membrane of the apical surface, from which release occurs. In type-III cells, after 4 or 5 h of treatment, dense-cored vesicles scattered throughout the cytoplasm tended to increase in number; they were often observed to accumulate in the vicinity of the Golgi apparatus. Five hours after treatment with 5-hydroxy-L-tryptophan (5-HTP) following colchicine pretreatment, monoamine specific fluorescent cells and vesicles with highly electron-dense cores of type-III cells were still present. On the other hand, 5 h after 5-HTP treatment alone both fluorescent cells and vesicles with highly electron-dense cores had already disappeared. These observations suggest that the treatment with colchicine interrupts the transport of dense-cored vesicles of type-III cells to synaptic areas, in which those vesicles are presumed to discharge the neurotransmitter substance.
authors.forename: M
authors.initials: M
authors.lastname: Takeda
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Y
authors.initials: Y
authors.lastname: Shishido
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D003078:Colchicine / Q000494:pharmacology*; D003594:Cytoplasmic Granules / Q000187:drug effects; D005453:Fluorescence; D051379:Mice; D008815:Mice, Inbred Strains; D008854:Microscopy, Electron; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D018377:Neurotransmitter Agents / Q000378:metabolism; D013650:Taste Buds / Q000187:drug effects / Q000648:ultrastructure*
chemical_list: D002395:Catecholamines; D018377:Neurotransmitter Agents; D003078:Colchicine