title: Local anesthetics suppress nerve growth factor-mediated neurite outgrowth by inhibition of tyrosine kinase activity of TrkA.
abstract: Local anesthetics (LAs) suppress sympathetic sprouting, which correlates with neuropathic pain. However, the precise mechanism of the suppression is unknown. Nerve growth factor (NGF) contributes to the sympathetic sprouting, and NGF signaling starts with NGF-stimulated autophosphorylation of TrkA, which is a high affinity receptor of NGF. We examined the effects of lidocaine, bupivacaine, and procaine on NGF signaling under suppression of NGF-stimulated neurite outgrowth in PC12 cells, which is a cellular model of sympathetic sprouting. To investigate the effect of these LAs on NGF-mediated neurite outgrowth of PC12 cells, cells were incubated with 40, 400, and 4000 microM of each LA. The effect of LAs on NGF-stimulated TrkA activity was examined to analyze autophosphorylation of TrkA using immunoprecipitation and immunoblotting. Cytotoxic effects of LAs on PC12 cells were also assessed by lactate dehydrogenase release and by propidium iodide staining. Lidocaine (400 microM), bupivacaine (40 and 400 microM), or procaine (4000 microM) suppressed either neurite outgrowth or autophosphorylation significantly without cytotoxicity. The inhibition of NGF-stimulated tyrosine kinase activity of TrkA might be involved in the mechanisms of suppression of neurite outgrowth induced by LAs.
authors.affiliation: Department of Anesthesiology, Kyoto Prefectural University of Medicine, Japan.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Takatori
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Munetaka
authors.initials: M
authors.lastname: Hirose
mesh_terms: D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D002045:Bupivacaine / Q000494:pharmacology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008012:Lidocaine / Q000494:pharmacology; D020932:Nerve Growth Factor / Q000494:pharmacology / Q000502:physiology*; D016501:Neurites / Q000187:drug effects / Q000502:physiology*; D016716:PC12 Cells / Q000187:drug effects; D010766:Phosphorylation; D011343:Procaine / Q000494:pharmacology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D020917:Receptor, trkA / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000779:Anesthetics, Local; D011343:Procaine; D020932:Nerve Growth Factor; D008012:Lidocaine; D007770:L-Lactate Dehydrogenase; D011505:Protein-Tyrosine Kinases; D020917:Receptor, trkA; D002045:Bupivacaine