Inhibition of fast axonal transport in vitro by the local anesthetics prilocaine, mepivacaine, and bupivacaine

1983 ◽  
Vol 61 (12) ◽  
pp. 1478-1482 ◽  
Author(s):  
P.-A. Lavoie
Keyword(s):  
Axonal Transport ◽  
Local Anesthetics ◽  
Liquid Scintillation ◽  
Conduction Block ◽  
Scintillation Counting ◽  
Fast Axonal Transport ◽  
Spinal Nerves ◽  
Transport Inhibitors

The aim of the present study was to establish the concentrations of prilocaine, mepivacaine, and bupivacaine which are effective at blocking fast axonal transport, to determine whether prilocaine and mepivacaine offer a better prospect of dissociating conduction block and transport block in vivo than does lidocaine and whether bupivacaine offers a better prospect than etidocaine in the same context. Fast axonal transport of [3H]leucine-labeled proteins was studied in vitro in bullfrog spinal nerves and quantitated by liquid scintillation counting. Exposure of spinal nerves to 14 mM prilocaine reduced the quantity of 3H-labeled proteins which accumulated at a ligature by 86%, and exposure to 14 mM mepivacaine reduced it by 70%; 10 mM prilocaine reduced this same parameter by 54%, a degree of inhibition close to the 44% reduction caused by 14 mM lidocaine. The D(−) and L(+) stereoisomers of mepivacaine each reduced transport to the ligature by approximately 50% at a concentration of 14 mM. Bupivacaine reduced the accumulation of 3H-labeled proteins at the ligature by 49% at a 10 mM concentration (pH 6.2); its potency is close to that found for etidocaine in a previous study. Since prilocaine and mepivacaine are at least as potent as lidocaine as transport inhibitors and at blocking impulse conduction, these two anesthetics offer no advantage over lidocaine to achieve dissociation of conduction block from transport block in vivo. Bupivacaine appears to offer no advantage over etidocaine in the same context, as the two agents have a similar potency as local anesthetics and a similar potency as inhibitors of fast axonal transport.

Continuation of fast axonal transport in regenerating axons in vitro

1979 ◽  
Vol 57 (11) ◽  
pp. 1251-1255
Author(s):  
M. A. Bisby ◽  
C. E. Hilton
Keyword(s):  
Sciatic Nerve ◽  
Vagus Nerve ◽  
Axonal Transport ◽  
Nerve Injury ◽  
Axon Regeneration ◽  
Free Medium ◽  
Fast Axonal Transport ◽  
Sensory Axons

A previous study by McLean and co-workers reported that regenerating axons of the rabbit vagus nerve were unable to sustain axonal transport in vitro for several months after nerve injury. In contrast, we found that sensory axons of the rat sciatic nerve were able to transport 3H-labeled protein into their regenerating portions distal to the site of injury within a week after injury when placed in vitro. Transport in vitro was not significantly less than transport in axons maintained in vivo for the same period. Transport occurred in the medium that was used by the McLean group, but was significantly reduced in calcium-free medium. When axon regeneration was delared, only small amounts of activity were present in the nerve distal to the site of injury, showing that labeled protein normally present in that part of the nerve was associated with axons and was not a result of local precursor uptake by nonneural elements in the sciatic nerve. We were not able to explain the failure of McLean and co-workers to demonstrate transport in vitro in regenerating vagus nerve, but we conclude that there is no general peculiarity of growing axons that makes them unable to sustain transport in vitro.

Importance of monovalent ions for the fast axonal transport of proteins

1981 ◽  
Vol 59 (1) ◽  
pp. 31-36 ◽  
Author(s):  
P.-A. Lavoie
Keyword(s):  
Axonal Transport ◽  
Dorsal Root Ganglia ◽  
Dorsal Root ◽  
Time Course ◽  
Protein Transport ◽  
Choline Chloride ◽  
Fast Axonal Transport ◽  
Spinal Nerves ◽  
Monovalent Ions

Proteins labeled with [35S] methionine or [3H]leucine were generated in vitro in bullfrog dorsal root ganglia and their fast axonal transport in the spinal nerves was followed during a subsequent incubation period. Incubation of the ganglia in a medium where sucrose, choline chloride, or sodium isethionate replaced NaCl caused respectively an 88, a 37, or a 76% reduction in the quantity of proteins carried by the fast axonal transport system; no decrease in synthesis of labeled proteins was observed and protein transport followed the usual time course. Incubation of desheathed spinal nerves in a medium where sucrose replaced NaCl reduced by 67% the quantity of labeled proteins which were transported past the desheathed region. Although both the axons and the dorsal root ganglia exhibit the requirement for monovalent ions to maintain fast axonal transport, the possibility that the ionic requirements of the ganglia pertain to the somal portion of the nerve cell is discussed.

scholarly journals Platelet Tagging with Tritium Labeled Diisopropylfluorophosphate

Blood ◽  
1965 ◽  
Vol 26 (6) ◽  
pp. 744-750 ◽  
Author(s):  
EDWARD ADELSON ◽  
RICHARD M. KAUFMAN ◽  
CIRO BERDEGUEZ ◽  
ARNOLD A. LEAR ◽  
JACK J. RHEINGOLD
Keyword(s):  
Liquid Scintillation ◽  
Survival Curve ◽  
Tritiated Water ◽  
Scintillation Counting ◽  
Saturation Point ◽  
Uptake Curve ◽  
Random Destruction ◽  
In Vitro Uptake

Abstract A method is described for tagging platelets either in vitro or in vivo with tritium labeled diisopropylfluorophosphate, burning the tagged platelets by a modification of the Schöniger combustion technic and counting the resultant tritiated water by liquid scintillation counting. The curve of in vitro uptake of DFP-H3 by the platelet suggests that more than one protein in or on the platelet takes up the DFP. However, a saturation point is reached, as indicated by a plateau in the uptake curve. The survival curve of in vivo tagged platelets in five normal dogs is exponential with a half-life of 2.4 days. This can be explained by random destruction of platelets or by elution of the tag. The DFP-H3 tag has several advantages over the DFP32 tag. Either smaller doses of DFP or higher levels of radioactivity or both may be achieved with this technic.

Effect of sodium- or chloride-deficient medium on fast axonal transport in frog spinal nerves

1982 ◽  
Vol 60 (1) ◽  
pp. 95-97 ◽  
Author(s):  
P.-A. Lavoie
Keyword(s):  
Axonal Transport ◽  
Choline Chloride ◽  
Fast Axonal Transport ◽  
Spinal Nerves ◽  
Deficient Medium ◽  
Sodium Isethionate

Fast axonal transport of radiolabeled proteins was studied in vitro in desheathed spinal nerves from frog. The replacement of the NaCl of the medium by LiCl reduced by 58% the amount of radiolabeled proteins which accumulated at a ligature, but its replacement by choline chloride did not inhibit transport. The replacement of NaCl by sodium isethionate led to a 32% reduction in the quantity of protein-bound radioactivity at the ligature. The results suggest that Cl ions are essential to maintain fast axonal transport, and that Na+ may also be important.

Inhibition of fast axonal transport in vitro by tetracaine: an increase in potency at alkaline pH, and no change in potency in calcium-depleted nerves

1982 ◽  
Vol 60 (12) ◽  
pp. 1715-1720 ◽  
Author(s):  
P.-A. Lavoie
Keyword(s):  
Axonal Transport ◽  
Local Anesthetics ◽  
Smooth Endoplasmic Reticulum ◽  
Calcium Content ◽  
Alkaline Ph ◽  
Ph Change ◽  
Fast Axonal Transport ◽  
The Relationship ◽  
Normal Calcium

Some of the present in vitro experiments compare the degree of inhibition of fast axonal transport produced by tetracaine at neutral and at alkaline pH. In desheathed spinal nerves from bullfrog, 0.5 mM tetracaine reduced the quantity of [3H]leucine-labeled proteins which were transported to a ligature by 43% at pH 7.2 and by 96% at pH 8.2; separate experiments established that transport was not affected by the pH change in the absence of tetracaine. The relationship between pH and transport-blocking potency of tetracaine (pKa 8.2) is such that the local anesthetic is more potent when more uncharged form of the molecule is present; this may reflect the easier penetration across the axonal plasma membrane by the uncharged form of the tetracaine molecule. The axonal smooth endoplasmic reticulum has been attributed the function of a calcium reservoir, and it appeared possible that local anesthetics could block axonal transport by releasing calcium from this structure. However, the inhibition of transport produced by 1 mM tetracaine (pH 7.1) in sheathed nerves was approximately 80% both in nerves with a lower than normal calcium content (47% of normal) and in nerves with a normal calcium content; this result does not support the hypothesis that inhibition of axonal transport by local anesthetics is mediated by an increase in intracellular free Ca2+, but does not rule out the hypothesis either.

scholarly journals Kinesin associates with anterogradely transported membranous organelles in vivo.

1991 ◽  
Vol 114 (2) ◽  
pp. 295-302 ◽  
Author(s):  
N Hirokawa ◽  
R Sato-Yoshitake ◽  
N Kobayashi ◽  
K K Pfister ◽  
G S Bloom ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Axonal Transport ◽  
Peripheral Nerves ◽  
In Vitro Studies ◽  
Immunogold Electron Microscopy ◽  
Precise Localization ◽  
Fast Axonal Transport ◽  
Immunocytochemical Studies

Biochemical, pharmacological and immunocytochemical studies have implicated the microtubule-activated ATPase, kinesin, in the movement of membrane bounded organelles in fast axonal transport. In vitro studies suggested that kinesin moves organelles preferentially in the anterograde direction, but data about the function and precise localization of kinesin in the living axon were lacking. The current study was undertaken to establish whether kinesin associates with anterograde or retrograde moving organelles in vivo. Peripheral nerves were ligated to produce accumulations of organelles moving in defined directions. Regions proximal (anterograde) and distal (retrograde) to the ligation were analyzed for kinesin localization by immunofluorescence, and by immunogold electron microscopy using ultracryomicrotomy. Substantial amounts of kinesin were associated with anterograde moving organelles on the proximal side, while significantly less kinesin was detected distally. Statistical analyses indicated that kinesin was mostly associated with membrane-bounded organelles. These observations indicate that axonal kinesin is primarily associated with anterograde moving organelles in vivo.

scholarly journals C9orf72-derived arginine-containing dipeptide repeats associate with axonal transport machinery and impede microtubule-based motility

2019 ◽  
Author(s):  
Laura Fumagalli ◽  
Florence L. Young ◽  
Steven Boeynaems ◽  
Mathias De Decker ◽  
Arpan R. Mehta ◽  
...  
Keyword(s):  
Axonal Transport ◽  
Motor Neurons ◽  
Single Molecule ◽  
Induced Pluripotent Stem Cell ◽  
Cytoplasmic Dynein ◽  
Inhibitory Interaction ◽  
Hexanucleotide Repeat ◽  
Repeat Expansions

ABSTRACTHexanucleotide repeat expansions in the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). How this mutation leads to these neurodegenerative diseases remains unclear. Here, we use human induced pluripotent stem cell-derived motor neurons to show that C9orf72 repeat expansions impair microtubule-based transport of mitochondria, a process critical for maintenance of neuronal function. Cargo transport defects are recapitulated by treating healthy neurons with the arginine-rich dipeptide repeat proteins (DPRs) that are produced by the hexanucleotide repeat expansions. Single-molecule imaging shows that these DPRs perturb motility of purified kinesin-1 and cytoplasmic dynein-1 motors along microtubules in vitro. Additional in vitro and in vivo data indicate that the DPRs impair transport by interacting with both microtubules and the motor complexes. We also show that kinesin-1 is enriched in DPR inclusions in patient brains and that increasing the level of this motor strongly suppresses the toxic effects of arginine-rich DPR expression in a Drosophila model. Collectively, our study implicates an inhibitory interaction of arginine-rich DPRs with the axonal transport machinery in C9orf72-associated ALS/FTD and thereby points to novel potential therapeutic strategies.

Sucrose Acetate Isobutyrate as an In situ Forming Implant for Sustained Release of Local Anesthetics

2019 ◽  
Vol 16 (4) ◽  
pp. 331-340
Author(s):  
Hanmei Li ◽  
Yuling Xu ◽  
Yuna Tong ◽  
Yin Dan ◽  
Tingting Zhou ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Sustained Release ◽  
Local Anesthetics ◽  
Subcutaneous Injection ◽  
In Vitro Release ◽  
Pharmacokinetic Analysis ◽  
Burst Release

Objective: In this study, an injectable Sucrose Acetate Isobutyrate (SAIB) drug delivery system (SADS) was designed and fabricated for the sustained release of Ropivacaine (RP) to prolong the duration of local anesthesia. Methods: By mixing SAIB, RP, and N-methyl-2-pyrrolidone, the SADS was prepared in a sol state with low viscosity before injection. After subcutaneous injection, the pre-gel solution underwent gelation in situ to form a drug-released depot. Result: The in vitro release profiles and in vivo pharmacokinetic analysis indicated that RP-SADS had suitable controlled release properties. Particularly, the RP-SADS significantly reduced the initial burst release after subcutaneous injection in rats. Conclusion: In a pharmacodynamic analysis of rats, the duration of nerve blockade was prolonged by over 3-fold for the RP-SADS formulation compared to RP solution. Additionally, RP-SADS showed good biocompatibility in vitro and in vivo. Thus, the SADS-based depot technology is a safe drug delivery strategy for the sustained release of local anesthetics with long-term analgesia effects.

scholarly journals De novo disease-associated mutations in KIF1A dominant negatively inhibit axonal transport of synaptic vesicle precursors

2021 ◽  
Author(s):  
Yuzu Anazawa ◽  
Tomoki Kita ◽  
Kumiko Hayashi ◽  
Shinsuke Niwa
Keyword(s):  
Synaptic Vesicle ◽  
Axonal Transport ◽  
De Novo ◽  
Molecular Motor ◽  
Model Systems ◽  
In Vitro Assays ◽  
In Vivo Model ◽  
Wild Type

KIF1A is a kinesin superfamily molecular motor that transports synaptic vesicle precursors in axons. Mutations in Kif1a lead to a group of neuronal diseases called KIF1A-associated neuronal disorder (KAND). KIF1A forms a homodimer and KAND mutations are mostly de novo and autosomal dominant; however, it is not known whether the function of wild-type KIF1A is inhibited by disease-associated KIF1A. No reliable in vivo model systems to analyze the molecular and cellular biology of KAND have been developed; therefore, here, we established Caenorhabditis elegans models for KAND using CRISPR/cas9 technology and analyzed defects in axonal transport. In the C. elegans models, heterozygotes and homozygotes exhibited reduced axonal transport phenotypes. In addition, we developed in vitro assays to analyze the motility of single heterodimers composed of wild-type KIF1A and disease-associated KIF1A. Disease-associated KIF1A significantly inhibited the motility of wild-type KIF1A when heterodimers were formed. These data indicate the molecular mechanism underlying the dominant nature of de novo KAND mutations.

scholarly journals α-Synuclein oligomers induce early axonal dysfunction in human iPSC-based models of synucleinopathies

2018 ◽  
Vol 115 (30) ◽  
pp. 7813-7818 ◽  
Author(s):  
Iryna Prots ◽  
Janina Grosch ◽  
Razvan-Marius Brazdis ◽  
Katrin Simmnacher ◽  
Vanesa Veber ◽  
...  
Keyword(s):  
Axonal Transport ◽  
Disease Patient ◽  
In Vivo Models ◽  
Human Neurons ◽  
Anterograde Axonal Transport ◽  
Axonal Dysfunction ◽  
Underlying Mechanisms ◽  
Human Ipsc

α-Synuclein (α-Syn) aggregation, proceeding from oligomers to fibrils, is one central hallmark of neurodegeneration in synucleinopathies. α-Syn oligomers are toxic by triggering neurodegenerative processes in in vitro and in vivo models. However, the precise contribution of α-Syn oligomers to neurite pathology in human neurons and the underlying mechanisms remain unclear. Here, we demonstrate the formation of oligomeric α-Syn intermediates and reduced axonal mitochondrial transport in human neurons derived from induced pluripotent stem cells (iPSC) from a Parkinson’s disease patient carrying an α-Syn gene duplication. We further show that increased levels of α-Syn oligomers disrupt axonal integrity in human neurons. We apply an α-Syn oligomerization model by expressing α-Syn oligomer-forming mutants (E46K and E57K) and wild-type α-Syn in human iPSC-derived neurons. Pronounced α-Syn oligomerization led to impaired anterograde axonal transport of mitochondria, which can be restored by the inhibition of α-Syn oligomer formation. Furthermore, α-Syn oligomers were associated with a subcellular relocation of transport-regulating proteins Miro1, KLC1, and Tau as well as reduced ATP levels, underlying axonal transport deficits. Consequently, reduced axonal density and structural synaptic degeneration were observed in human neurons in the presence of high levels of α-Syn oligomers. Together, increased dosage of α-Syn resulting in α-Syn oligomerization causes axonal transport disruption and energy deficits, leading to synapse loss in human neurons. This study identifies α-Syn oligomers as the critical species triggering early axonal dysfunction in synucleinopathies.

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