Further evidence for the involvement of microtubules in the intra-axonal movement of noradrenaline storage granules.
1. Constricted cat hypogastric nerve/inferior mesenteric ganglion preparations maintained in vitro for 48 hr have been used to study the effects of different concentrations of colchicine on axonal microtubules and on the proximo-distal movement of catecholamine containing dense-cored vesicles in non-myelinated axons.2. In low concentrations (0.03-0.3 mug/ml.), colchicine had no effect on the number of microtubules per axon and did not diminish the amount of noradrenaline accumulating proximal to the constriction.3. Higher concentrations of colchicine (1.0-10 mug/ml.) produced a dramatic reduction in the number of microtubules per axon. This was associated with marked reductions in the number of dense-cored vesicles and the amount of noradrenaline accumulating above the constriction.4. There was some morphological evidence for a structural relationship between dense-cored vesicles and microtubules.5. These results further support the view that axonal microtubules are involved in the relatively fast proximo-distal transport of noradrenaline containing dense-cored vesicles in non-myelinated sympathetic axons.
D000818:Animals; D001370:Axonal Transport; D001369:Axons / Q000187:drug effects / Q000378:metabolism; D002415:Cats; D003078:Colchicine / Q000494:pharmacology; D003594:Cytoplasmic Granules / Q000378:metabolism*; D008854:Microscopy, Electron; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D013194:Staining and Labeling; D013564:Sympathetic Nervous System / Q000378:metabolism
D003078:Colchicine; D009638:Norepinephrine