Adrenergic Nerve Fibers in the Human Fetal Sciatic Nerve

Objective: The present study was designed to determine the neuroprotective effect of Abelmoschus esculentus L. on alloxan-induced diabetic neuropathy in rats.Methods: Diabetes was induced in rats with a single intraperitoneal injection of alloxan monohydrate (130 mg/kg b.w). The ethanol extract of A. esculentus L. at a dose of 100 and 200 mg/kg of body weight was administered at single dose per day to alloxan-induced diabetic rats for 21 days. The fasting blood glucose was screened in the intermittent on day 0, day 14, and day 21. Behavioral tests such as thermal hyperalgesia test and rotarod performance test were performed to assess the thermal sensitivity and muscle grip strength. At the end of the study period, experimental animals were sacrificed and sciatic nerve tissues were obtained for histopathological investigation.Results: Animals treated with A. esculentus L. extarct at a dose of 200 mg/kg of body weight significantly reduced (p<0.05) in hyperglycemia and thermal hyperalgesia and significantly increased (p<0.05) in rotarod performance. The sciatic nerve fiber of diabetic rats receiving 200 mg/kg of body weight of A. esculentus L. extract also shows no swelling of nerve fibers, and lesser demyelination was observed.Conclusion: These findings demonstrate that A. esculentus L. exhibits significant antidiabetic and neuroprotective effect against alloxan-induced diabetic neuropathy in rats.

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Amitriptyline Neurotoxicity

Anesthesiology ◽

10.1097/00000542-200406000-00026 ◽

2004 ◽

Vol 100 (6) ◽

pp. 1519-1525 ◽

Cited By ~ 41

Author(s):

Jean-Pierre Estebe ◽

Robert R. Myers

Keyword(s):

Nervous System ◽

Sciatic Nerve ◽

Local Anesthetic ◽

Dose Range ◽

Antidepressant Drug ◽

Nerve Fibers ◽

Anesthetic Agent ◽

Sprague Dawley ◽

Neurotoxic Effect ◽

Local Anesthetic Agent

Background Amitriptyline is a tricyclic antidepressant drug used systemically for the management of neuropathic pain. Antidepressants, as a class of drugs with direct neurologic actions, are becoming widely used for the management of chronic pain, although their mechanisms are not entirely understood. Amitriptyline exerts potent effects on reuptake of norepinephrine and serotonin and blocks alpha 2A adrenoreceptors and N-methyl-D-aspartate receptors. Because amitriptyline is also a particularly potent blocker of sodium channels and voltage-gated potassium and calcium channels, it has been recommended as a long-acting local anesthetic agent. Unfortunately, amitriptyline has significant toxic side effects in the central nervous system and cardiovascular system that are dose-related to its systemic administration. Therefore, before amitriptyline can be used clinically as a local anesthetic agent, it should be thoroughly explored with respect to its direct neurotoxic effect in the peripheral nervous system. Methods The left sciatic nerve of Sprague-Dawley rats (12/ group) received a single topical amitriptyline dose of 0.625, 1.25, 2.5, or 5 mg; a saline group (n = 2) was used as control. Neuropathologic evaluations were conducted in separate animals (n = 4) 1, 3, and 7 days later. Results Amitriptyline topically applied in vivo to rat sciatic nerve causes a dose-related neurotoxic effect. Drug doses of 0.625-5 mg all caused Wallerian degeneration of peripheral nerve fibers, with the number of affected fibers and the severity of the injury directly related to the dose. Conclusion Because the effective local anesthetic dose is within this dose range, the authors strongly recommend that amitriptyline not be used as a local anesthetic agent.

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Substance P-, CGRP- and NPY-immunoreactive nerve fibers in rat sciatic nerve-end neuromas

Regulatory Peptides ◽

10.1016/0167-0115(89)90244-9 ◽

1989 ◽

Vol 25 (1) ◽

pp. 11-24 ◽

Cited By ~ 24

Author(s):

K. Fried ◽

E. Brodin ◽

E. Theodorsson

Keyword(s):

Substance P ◽

Sciatic Nerve ◽

Nerve Fibers ◽

Rat Sciatic Nerve

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Degeneration and Regrowth of Adrenergic Nerve Fibers in the Rat Peripheral Tissues after 6-Hydroxydopamine

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y71-038 ◽

1971 ◽

Vol 49 (4) ◽

pp. 345-355 ◽

Cited By ~ 102

Author(s):

J. de Champlain

Keyword(s):

Ganglion Cells ◽

Adrenergic Innervation ◽

Nerve Fibers ◽

Adrenergic Nerve ◽

High Dose ◽

Rat Tissues ◽

Peripheral Tissues ◽

Endogenous Noradrenaline ◽

6 Hydroxydopamine ◽

Noradrenaline Levels

Histofluorescent and biochemical changes in the adrenergic nervous system were followed up in rat tissues after one single intravenous injection of a high dose of 100 mg/kg of 6-hydroxydopamine (6-OH-DA). This treatment results in the rapid disappearance of terminal and preterminal fibers in the iris, atria, and small arteries of rats, whereas endogenous noradrenaline pools of the heart are 95% depleted. The capacity of the adrenergic nerve to take up and accumulate tritiated noradrenaline is reduced proportionally to the reduction in endogenous noradrenaline levels. These changes are compatible with the concept of a complete sympathectomy induced by the specific toxic action of 6-OH-DA on the adrenergic fibers. This sympathectomy is not permanent, however, and numerous bundles of preterminal fibers start to grow in the iris and atria within 4 to 5 days following injection. Progressively, in the following weeks, these fibers distribute over the whole organ and give birth to terminal fibers which form a new adrenergic plexus in these tissues. A completely normal innervation is restored 2 to 3 months after administration of 6-OH-DA. The endogenous noradrenaline levels rise progressively in parallel to the development of the new plexus of fibers. Since a complete regeneration of the adrenergic innervation can be demonstrated in the weeks following injection of 6-OH-DA, it appears that this compound can selectively destroy the adrenergic terminal and preterminal fibers without causing a degeneration of the adrenergic ganglion cells.

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Electron Microscopy Analysis of Sciatic Nerve Fibers in C57BL/6 Transgenic Mice

Neurophysiology ◽

10.1007/s11062-020-09857-2 ◽

2020 ◽

Vol 52 (2) ◽

pp. 94-100

Author(s):

I. O. Govbakh ◽

O. M. Tsupykov ◽

E. G. Smozhanik ◽

V. V. Rubtsov ◽

M. Tymchyshin ◽

...

Keyword(s):

Electron Microscopy ◽

Sciatic Nerve ◽

Transgenic Mice ◽

Nerve Fibers ◽

Electron Microscopy Analysis ◽

Microscopy Analysis

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Galanin is localized in sympathetic neurons of the dog liver

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1997.273.6.e1194 ◽

1997 ◽

Vol 273 (6) ◽

pp. E1194-E1202 ◽

Cited By ~ 2

Author(s):

Thomas O. Mundinger ◽

C. Bruce Verchere ◽

Denis G. Baskin ◽

Michael R. Boyle ◽

Stephan Kowalyk ◽

...

Keyword(s):

Blood Vessels ◽

Sympathetic Neurons ◽

Sympathetic Nerves ◽

Liver Parenchyma ◽

Nerve Fibers ◽

Adrenergic Nerve ◽

Adrenergic Nerve Terminals ◽

6 Hydroxydopamine ◽

Hepatic Nerves ◽

Dog Liver

Stimulation of canine hepatic nerves releases the neuropeptide galanin from the liver; therefore, galanin may be a sympathetic neurotransmitter in the dog liver. To test this hypothesis, we used immunocytochemistry to determine if galanin is localized in hepatic sympathetic nerves and we used hepatic sympathetic denervation to verify such localization. Liver sections from dogs were immunostained for both galanin and the sympathetic enzyme marker tyrosine hydroxylase (TH). Galanin-like immunoreactivity (GALIR) was colocalized with TH in many axons of nerve trunks as well as individual nerve fibers located both in the stroma of hepatic blood vessels and in the liver parenchyma. Neither galanin- nor TH-positive cell bodies were observed. Intraportal 6-hydroxydopamine (6-OHDA) infusion, a treatment that selectively destroys hepatic adrenergic nerve terminals, abolished the GALIR staining in parenchymal neurons but only moderately diminished the GALIR staining in the nerve fibers around blood vessels. To confirm that 6-OHDA pretreatment proportionally depleted galanin and norepinephrine in the liver, we measured both the liver content and the hepatic nerve-stimulated spillover of galanin and norepinephrine from the liver. Pretreatment with 6-OHDA reduced the content and spillover of both galanin and norepinephrine by >90%. Together, these results indicate that galanin in dog liver is primarily colocalized with norepinephrine in sympathetic nerves and may therefore function as a hepatic sympathetic neurotransmitter.

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