Blood flow in the sciatic nerve is regulated by vasoconstrictive and vasodilative nerve fibers originating from the ventral and dorsal roots of the spinal nerves

1994 ◽  
Vol 21 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Akio Sato ◽  
Yuko Sato ◽  
Sae Uchida
1993 ◽  
Vol 265 (4) ◽  
pp. H1155-H1159
Author(s):  
Y. Kinoshita ◽  
W. W. Monafo

The spinal cord vasculature is innervated by noradrenergic nerve fibers, the role of which in the regulation of regional spinal cord blood flow (RSCBF) is presently unclear. We used the distribution of [14C]butanol to simultaneously measure RSCBF at seven cord levels and the regional blood flow in sciatic nerve (NBF), truncal skin, and biceps femoris muscle. The subjects were control rats and rats that had been given parenteral guanethidine sulfate for 5 wk to induce selective postganglionic "chemical sympathectomy." Flows were measured under basal conditions (group I) and immediately after an arterial hemorrhage (group II). The results indicate that RSCBF was unchanged from control after guanethidine administration in both groups; however, NBF was elevated after guanethidine by 47% in group I and by 41% in group II. We conclude that in the spinal cord as in the brain, sympathetic inflow does not appear to have an important role in the regulation of regional blood flow. Sympathetic inflow appears to partly regulate NBF, however, probably by varying vascular tone.


Author(s):  
John L. Beggs ◽  
Peter C. Johnson ◽  
Astrid G. Olafsen ◽  
C. Jane Watkins

The blood supply (vasa nervorum) to peripheral nerves is composed of an interconnected dual circulation. The endoneurium of nerve fascicles is maintained by the intrinsic circulation which is composed of microvessels primarily of capillary caliber. Transperineurial arterioles link the intrinsic circulation with the extrinsic arterial supply located in the epineurium. Blood flow in the vasa nervorum is neurogenically influenced (1,2). Although a recent hypothesis proposes that endoneurial blood flow is controlled by the action of autonomic nerve fibers associated with epineurial arterioles (2), our recent studies (3) show that in addition to epineurial arterioles other segments of the vasa nervorum are also innervated. In this study, we examine blood vessels of the endoneurium for possible innervation.


1972 ◽  
Vol 48 (10) ◽  
pp. 747-752 ◽  
Author(s):  
Masanori OTSUKA ◽  
Shiro KONISHI ◽  
Tomoyuki TAKAHASHI
Keyword(s):  

1991 ◽  
Vol 140 (4) ◽  
pp. 369-372 ◽  
Author(s):  
J. Koistinaho

Author(s):  
Lee Wei Yang ◽  
Santosh Fattepur ◽  
Kiran Chanabasappa Nilugal ◽  
Fadli Asmani ◽  
Eddy Yusuf ◽  
...  

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.


2015 ◽  
Vol 39 (3) ◽  
pp. E14 ◽  
Author(s):  
Stepan Capek ◽  
Benjamin M. Howe ◽  
Kimberly K. Amrami ◽  
Robert J. Spinner

OBJECT Perineural spread along pelvic autonomie nerves has emerged as a logical, anatomical explanation for selected cases of neoplastic lumbosacral plexopathy (LSP) in patients with prostate, bladder, rectal, and cervical cancer. The authors wondered whether common radiological and clinical patterns shared by various types of pelvic cancer exist. METHODS The authors retrospectively reviewed their institutional series of 17 cases concluded as perineural tumor spread. All available history, physical examination, electrodiagnostic studies, biopsy data and imaging studies, evidence of other metastatic disease, and follow-up were recorded in detail. The series was divided into 2 groups: cases with neoplastic lumbosacral plexopathy confirmed by biopsy (Group A) and cases included based on imaging characteristics despite the lack of biopsy or negative biopsy results (Group B). RESULTS Group A comprised 10 patients (mean age 69 years); 9 patients were symptomatic and 1 was asymptomatic. The L5–S1 spinal nerves and sciatic nerve were most frequently involved. Three patients had intradural extension. Seven patients were alive at last follow-up. Group B consisted of 7 patients (mean age 64 years); 4 patients were symptomatic, 2 were asymptomatic, and 1 had only imaging available. The L5–S1 spinal nerves and the sciatic nerve were most frequently involved. No patients had intradural extension. Four patients were alive at last follow-up. CONCLUSIONS The authors provide a unifying theory to explain lumbosacral plexopathy in select cases of various pelvic neoplasms. The tumor cells can use splanchnic nerves as conduits and spread from the end organ to the lumbosacral plexus. Tumor can continue to spread along osseous and muscle nerve branches, resulting in muscle and bone “metastases.” Radiological studies show a reproducible, although nonspecific pattern, and the same applies to clinical presentation.


2004 ◽  
Vol 100 (6) ◽  
pp. 1519-1525 ◽  
Author(s):  
Jean-Pierre Estebe ◽  
Robert R. Myers

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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