Axoplasmic transport

Microtubules are universally present in eukaryotes from protozoa to the cells of higher animals and plants (Porter, 1966 Hardham and Gunning, 1978 Lloyd, 1987), but they are absent in mammalian erythrocytes and in prokaryotes. Microtubules participate in a number of cellular functions including the maintenance of cell shape and polarity, mitosis, cytokinesis, the positioning of organelles, intracellular transport to specific domains, axoplasmic transport, and cell locomotion. The diversity of microtubule fimctions suggests that not all microtubules are identical and that different classes of microtubules are present in different cell types or are localized in distinct domains in the same cell type (Ginzburg et al., 1989). 

Another example of parallel arrays of microtubules but with a much looser pattern is provided by axons, showing the involvement of such arrays in axoplasmic transport. This is illustrated in Figure 3. 

The cytoskeleton is involved in anterograde and retrograde axoplasmic transport (Hollenbeck, 1989 Coy and Howard, 1994). 

Lasek, R. J. and Brady, S. T. The Structural Hypothesis of axonal transport Two classes of moving elements. In D. G. Weiss (ed.), Axoplasmic Transport. Berlin Springer-Verlag, 1982, pp. 397-405. 

Mendell JR, Sahenk Z, Saida K, et al. 1977. Alterations of fast axoplasmic transport in experimental methyl n-butyl ketone neuropathy. Brain Res 133 107-118. 

Beitner-Johnson, Dana, and Eric J. Nestler. 1993. "Chronic Morphine Impairs Axoplasmic Transport in the Rat Mesolimbic Dopamine System." Neuroreport 5 57-60. 

Fast anterograde transport can reach rates as high as 400 mm/day. It is dependent upon microtubules that provide a track along which the vesicles move. The movement is energy dependent and is mediated by a specific motor protein, kinesin. A similar process is responsible for fast retrograde transport. A second motor protein, dynein, is needed for movement in that direction. A third type of transport process is termed slow axoplasmic transport. It ranges from 0.2 to 5 mm/day and is responsible for the transport of cytoskeletal proteins, the neurofilaments, and microtubules, as well as an assortment of cytoplasmic proteins. 

Hansen HS, Aitmann A (2008) Endocannabrnoids and nutrition. J Neuroendocrinol 20 94—99 Hansson HA, Rozell B, Skottner A (1987) Rapid axoplasmic transport of insulin-like growth factor 1 in the sdatic nerve af adult rats. Cell Tissue Res 247 241—247 I [anus L, Abu-Lafi S, Fride E, Breuer A, Vogel Z, Shalev DE, Kustanovich 1, Mechoulam R (2001) 2-Arachidonyl glyceryl ether, an endogenous agonist of the cannabinoid CBl receptor. Pioc Natl Acad Sd U S A 98 3662-3665... 

England, J.D., Asbury, A.K., Rhee, E.K., Sumner, A.J. (1988). Lethal retrograde axoplasmic transport of doxorubicin (adria-mycin) to motor neurons. A toxic motor neuronopathy. Brain 111 (Pt 4) 915-26. 

The pathogenesis of vincristine-induced neuropathy has not been fully elucidated, but very probably altered axoplasmic transport processes are of major importance, since neurons treated with vincristine lose portions of their axonal microtubules (35). There is marked interindividual variability in sensitivity to this toxic effect, partially based on different predisposing factors, for example diabetes mellitus, pretreatment with other potentially neurotoxic agents (such as cisplatin and taxanes), or familial disorders (such as Charcot-Marie-Tooth syndrome) (37,51,52). 

Ochs S, Jersild RA, Breen T, et al. 1986. The maintenance of axoplasmic transport by strontium and its localization in nerve fibers. JNeurobiol 17(1) 55-61. 

Hansson, H.A., Rozell, B. and Skottner, A. (1987) Rapid axoplasmic transport of insulin-like growth factor 1 in the sciatic nerve of adult rats. Cell Tissue Res. 247 241-247. 

Sandeman DC, Denburg JL (1976) The central projections of chemoreceptor axons in the crayfish revealed by axoplasmic transport. Brain Res 115 492-496... 

Gamse, R., Lembeck, F., and Cuello, A. C., 1979ft, Substance P in the vagus nerve immunochemical and immunohistochemical evidence for axoplasmic transport, Naunyn-Schmiedeberg s Arch. Pharmacol. 306 37-44. 

Cytochromes are responsible for electron transport and oxidative phosphorylation yielding adenosine triphosphate needed for vital processes such as protein synthesis, maintenance of the resting membrane potential, and rapid axoplasmic transport within neurones (Ochs and Ranish 1970, Ochs and Holligsworth 1971). 

Mitigation of nociception via transganglionic degenerative atrophy possible mechanism of vinpocetine-induced blockade of retrograde axoplasmic transport. Annals of Anatomy. 190 140-145. 

Abbott W, Meister A (1986) Intrahepatic transport and utilization of biliary glutathione and its metabolites. Proc Natl Acad Sci USA 83 1246-1250 Abe T, Haga T, Kurokawa M (1975) Blockage of axoplasmic transport and depolymerization of reassembled microtubules by methylmercury. Brain Res 86 504-508... 

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