[14C]butanol distribution: a new method for measurement of spinal cord blood flow

[14C]butanol distribution was used to quantitate regional blood flow (SCBF) in the spinal cord (levels T3-5, T7-9, L1-2, L3-S) and in the sciatic nerves (NBF) of control pentobarbital sodium-anesthetized rats (group A), after 1 h of hemorrhagic hypotension (group B), after 15 min of stimulation of one sciatic nerve (group C-1), and after stimulation of one sciatic nerve plus hemorrhage, which maintained mean arterial pressure (MAP) at control (130 mmHg). Group A SCBF ranged from 52.3 +/- 3.5 (L3-S) to 67.4 +/- 2.7 (L1-2) ml.min-1.100 g-1. NBF was 8.0 +/- 0.9 ml.min-1.100 g-1. Group B SCBF was unchanged. NBF fell to 4.0 +/- 0.4 ml.min-1.100 g-1. Group C-1 SCBF was markedly elevated (range 122 +/- 23.1 to 150.1 +/- 18.7 ml.min-1.100 g-1). NBF was 33.5 +/- 4.1 ml.min-1.100 g-1 (stimulated side) and 14.7 +/- 1.4 ml.min-1.100 g-1 (nonstimulated). MAP was elevated (163 +/- 6 mmHg). In group C-2 (MAP was 130 +/- 4 mmHg), SCBF was still elevated at T3-5, L3-S, and marginally elevated at L1-2. NBF was 22.6 +/- 4.7 ml.min-1.100 g-1 (stimulated) but unchanged contralaterally. [14C]butanol distribution provides a sensitive reproducible measure of SCBF and NBF. Autoregulation of SCBF (but not of NBF) occurred in the range 60-160 mmHg MAP. Spinal cord stimulation via the sciatic nerve increased SCBF two- to threefold, but when hypertension was avoided by blood withdrawal, a modest (38%) increase in SCBF still occurred.

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Regional blood flow in the brain and spinal cord of hypothermic rats

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1989.257.3.h785 ◽

1989 ◽

Vol 257 (3) ◽

pp. H785-H790

Author(s):

T. Sakamoto ◽

W. W. Monafo

Keyword(s):

Spinal Cord ◽

Blood Flow ◽

Brain Stem ◽

Regional Blood Flow ◽

Experimental Conditions ◽

Pentobarbital Sodium ◽

Arterial Blood ◽

Group A ◽

Group B ◽

The Brain

[14C]butanol tissue uptake was used to measure simultaneously regional blood flow in three regions of the brain (cerebral and cerebellar hemispheres and brain stem) and in five levels of the spinal cord in 10 normothermic rats (group A) and in 10 rats in which rectal temperature had been lowered to 27.7 +/- 0.3 degrees C by applying ice to the torso (group B). Pentobarbital sodium anesthesia was used. Mean arterial blood pressure varied minimally between groups as did arterial pH, PO2, and PCO2. In group A, regional spinal cord blood flow (rSCBF) varied from 49.7 +/- 1.6 to 62.6 +/- 2.1 ml.min-1.100 g-1; in brain, regional blood flow (rBBF) averaged 74.4 +/- 2.3 ml.min-1.100 g-1 in the whole brain and was highest in the brain stem. rSCBF in group B was elevated in all levels of the cord by 21-34% (P less than 0.05). rBBF, however, was lowered by 21% in the cerebral hemispheres (P less than 0.001) and by 14% in the brain as a whole (P less than 0.05). The changes in calculated vascular resistance tended to be inversely related to blood flow in all tissues. We conclude that rBBF is depressed in acutely hypothermic pentobarbital sodium-anesthetized rats, as has been noted before, but that rSCBF rises under these experimental conditions. The elevation of rSCBF in hypothermic rats confirms our previous observations.

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Regional blood flow in transected rat spinal cord during hypothermia

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1990.259.6.h1649 ◽

1990 ◽

Vol 259 (6) ◽

pp. H1649-H1654

Author(s):

T. Sakamoto ◽

A. Iwai ◽

W. W. Monafo

Keyword(s):

Spinal Cord ◽

Blood Flow ◽

Sciatic Nerve ◽

Rectal Temperature ◽

Regional Blood Flow ◽

Spinal Cord Transection ◽

The Other ◽

Rat Spinal Cord ◽

Caudal Spinal Cord

Regional blood flow (RBF) increases in the spinal cord and sciatic nerve of acutely hypothermic rats. To determine whether cord transection affects this response, we measured RBF in rat spinal cord and sciatic nerve 2 h after cord transection at vertebrae T8 (n = 18 rats) and T11 (n = 18 rats) using [14C]butanol distribution. Nine in each group were normothermic controls. In T11 transection-hypothermia (25-27 degrees C rectal temperature), RBF increased in the three rostral cord segments by 28-40% (P less than 0.05); caudally, cord RBF was depressed in two segments (P less than 0.05), unchanged in the other; RBF fell in nerve (P less than 0.05). In T8 transection-hypothermia, RBF was unchanged in the two rostral cord segments; caudally, RBF was depressed in one cord segment (P less than 0.05) and unchanged in the others; RBF was unchanged in nerve. We conclude that RBF does not rise in caudal spinal cord segments or in sciatic nerve during hypothermia in rats with prior spinal cord transection.

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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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Regional sciatic nerve blood flow response to limb movement

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1987.252.2.h439 ◽

1987 ◽

Vol 252 (2) ◽

pp. H439-H441

Author(s):

H. Sugimoto ◽

W. W. Monafo ◽

S. Shimazaki

Keyword(s):

Blood Flow ◽

Regional Blood Flow ◽

Biceps Femoris ◽

Nerve Blood Flow ◽

Blood Flows ◽

Flow Response ◽

Sciatic Nerves ◽

Direct Nerve ◽

Normal Controls ◽

Stimulation Of

The regional blood flow in the sciatic nerves (NBF), biceps femoris muscles (MBF), and hind limb skin (SBF) was measured simultaneously in anesthetized, normal rats, in other rats immediately after 15 min of electrical stimulation of one sciatic trunk (10 shocks/s), and in a group of similarly stimulated but previously curarized rats. These experiments were done to quantitate NBF during direct nerve stimulation in both the presence and absence of associated vigorous limb twitching, as these relationships have not previously been examined. Tissue blood flows were measured by an “indicator-fractionation” technic, using the distribution of [14C]butanol. NBF in normal controls was 11.1 +/- 1.4 ml X min-1 X 100 g-1; MBF was 6.8 +/- 0.6 ml X min-1 X 100 g-1. In the stimulated limb of noncurarized rats, NBF rose to 19.8 +/- 3.5 ml X min-1 X 100 g-1. MBF was elevated approximately tenfold. SBF also rose. In stimulated limbs of curarized rats, NBF was also approximately double the resting normal value, 23.2 +/- 4.8 ml X min-1 X 100 g-1, but MBF was then only slightly increased. We conclude that sciatic NBF increases appreciably when this nerve is stimulated, irrespective, for the most part, of whether limb motor activity is increased. The vascular mechanisms which regulate NBF differ from and are largely independent of those regulating MBF.

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Effect of acute spinal cord compression injury on regional spinal cord blood flow in primates

Journal of Neurosurgery ◽

10.3171/jns.1976.45.6.0660 ◽

1976 ◽

Vol 45 (6) ◽

pp. 660-676 ◽

Cited By ~ 144

Author(s):

Alan N. Sandler ◽

Charles H. Tator

Keyword(s):

Spinal Cord ◽

Blood Flow ◽

White Matter ◽

Cord Blood ◽

Gray Matter ◽

Regional Blood Flow ◽

Compression Injury ◽

Spinal Cord Blood Flow ◽

Content Type ◽

Cord Injury

✓ Spinal cord blood flow (SCBF) was measured in 24 rhesus monkeys after injury to the cord produced by the inflatable circumferential extradural cuff technique. Measurement of regional blood flow in the white and gray matter of the cord in areas of 0.1 sq mm was achieved with the 14C-antipyrine autoradiographic technique and a scanning microscope photometer. After moderate cord injury (400 mm Hg pressure in the cuff maintained for 5 minutes), which produced paraplegia in 50% of animals and moderate to severe paresis in the other 50%, mean white matter SCBF was significantly decreased for up to 1 hour. White matter blood flow then rose to normal levels by 6 hours posttrauma and was significantly increased by 24 hours posttrauma. Gray matter SCBF was significantly decreased for the entire 24-hour period post-trauma. After severe cord injury (150 mm Hg pressure in the cuff maintained for 3 hours), which produced total paraplegia in almost all animals, SCBF in white and gray matter was reduced to extremely low levels for 24 hours posttrauma. In addition, focal decreases in SCBF were seen in white and gray matter for considerable distances proximal and distal to the injury site. It is concluded that acute compression injury of the spinal cord is associated with long-lasting ischemia in the cord that increases in severity with the degree of injury.

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