Effects of graded mechanical compression of rabbit sciatic nerve on nerve blood flow and electrophysiological properties

Rb86 and Iodo131 antipyrine were injected together by vein in rats. The brain, spinal cord, and nerve contents of each label were measured 30 or 60 sec later. Iodoantipyrine values were used to calculate blood flow to these portions of the nervous system. The ratio of Rb86 to iodoantipyrine uptake was used as an index of the efficacy of the hematoneural barrier. The barrier is most complete in the brain, less complete in the spinal cord, and absent in peripheral nerve. Blood flow values per gram are: brain .41 ml/g min; cord .28 ml/g min, and nerve .11 ml/g min. It is suggested that the blood-brain barrier is an anatomical entity rather than a functional one.

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Blood Flow in Mobilized Nerves: Results in a Rabbit Sciatic Nerve Model

Plastic & Reconstructive Surgery ◽

10.1097/00006534-199709000-00014 ◽

1997 ◽

Vol 100 (3) ◽

pp. 634,635

Author(s):

G??ran Lundborg

Keyword(s):

Blood Flow ◽

Sciatic Nerve ◽

Nerve Model ◽

Rabbit Sciatic Nerve

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Effects of adrenergic stimulation on sciatic nerve blood flow in diabetic and control rats

European Journal of Pharmacology ◽

10.1016/s0014-2999(97)89176-5 ◽

1997 ◽

Vol 329 (2-3) ◽

pp. 147-152 ◽

Cited By ~ 3

Author(s):

Phuong A. Vo ◽

David R. Tomlinson

Keyword(s):

Blood Flow ◽

Sciatic Nerve ◽

Adrenergic Stimulation ◽

Nerve Blood Flow ◽

And Control

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Guanethidine chemical sympathectomy: spinal cord and sciatic nerve blood flow

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1993.265.4.h1155 ◽

1993 ◽

Vol 265 (4) ◽

pp. H1155-H1159

Author(s):

Y. Kinoshita ◽

W. W. Monafo

Keyword(s):

Spinal Cord ◽

Blood Flow ◽

Sciatic Nerve ◽

Regional Blood Flow ◽

Nerve Fibers ◽

Chemical Sympathectomy ◽

Nerve Blood Flow ◽

Biceps Femoris Muscle ◽

Group I ◽

Group Ii

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.

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Increased sciatic nerve blood flow in diabetic rats: assessment by "molecular" vs. particulate microspheres

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1997.273.1.e164 ◽

1997 ◽

Vol 273 (1) ◽

pp. E164-E173 ◽

Cited By ~ 4

Author(s):

K. Chang ◽

Y. Ido ◽

W. LeJeune ◽

J. R. Williamson ◽

R. G. Tilton

Keyword(s):

Blood Flow ◽

Sciatic Nerve ◽

Reference Sample ◽

Streptozotocin Diabetes ◽

Diabetic Rats ◽

Nerve Blood Flow ◽

Doppler Flowmetry ◽

Blood Flows ◽

Microsphere Method ◽

Onset Of Diabetes

Sciatic nerve blood flow in diabetic rats in typically increased or unchanged when assessed by the reference sample microsphere method in our laboratory. In contrast, blood flow is generally reported to be decreased approximately 50% when assessed with laser Doppler flowmetry or hydrogen clearance polarography. To address concerns that increased blood flow observed with microspheres might be anomalous because of their particulate nature and/or because insufficient numbers of microspheres are captured in the nerve, a plasma-soluble "molecular microsphere" ([3H]desmethylimipramine, mol wt = 266) and 11.3-micron 153Gd-labeled microspheres were injected sequentially to assess blood flow in rats with streptozotocin diabetes of 2-4 wk duration. Nerve blood flows in diabetic rats were increased 1.5- to 2-fold (vs. control rats) with both tracers; these increases were prevented by tolrestat, an inhibitor of aldose reductase. These observations indicate that blood flow in sciatic nerve (like that in retina and kidney) is increased early after the onset of diabetes and is 1) demonstrable with a plasma-soluble tracer as well as with particulate microspheres and 2) linked to increased metabolism of glucose via the sorbitol pathway.

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The Effect of Electrical Stimulation of the Pudendal Nerve on Sciatic Nerve Blood Flow in Animals

Acupuncture in Medicine ◽

10.1136/aim.26.3.145 ◽

2008 ◽

Vol 26 (3) ◽

pp. 145-148 ◽

Cited By ~ 7

Author(s):

Motohiro Inoue ◽

Tatsuya Hojo ◽

Miwa Nakajima ◽

Hiroshi Kitakoji ◽

Megumi Itoi ◽

...

Keyword(s):

Blood Pressure ◽

Blood Flow ◽

Electrical Stimulation ◽

Sciatic Nerve ◽

Pudendal Nerve ◽

Systemic Blood Pressure ◽

Nerve Blood Flow ◽

Doppler Flowmetry ◽

Canal Stenosis ◽

Stimulation Of

Objective To investigate the mechanism of the clinical effect of electroacupuncture of the pudendal nerve on the lumbar and lower limb symptoms caused by lumbar spinal canal stenosis, we studied changes in sciatic nerve blood flow during electrical stimulation of the pudendal nerve in the rat. Methods Using rats (n=5), efferent electrical stimulation to the pudendal nerve was performed and sciatic nerve blood flow was measured with laser Doppler flowmetry. Simultaneously, changes in the blood pressure and cardiac rate were measured. Furthermore, the effect of atropine on these responses to the stimulation was also studied. Results Electrical stimulation of the pudendal nerve significantly increased blood flow in the sciatic nerve transiently without increasing heart rate and systemic blood pressure. The significant increase in the sciatic nerve blood flow disappeared after administration of atropine. Conclusion Electrical stimulation of the pudendal nerve causes a transient and significant increase in sciatic nerve blood flow. This response is eliminated or attenuated by administration of atropine, indicating that it occurs mainly via cholinergic nerves.

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