Regional sciatic nerve blood flow response to limb movement

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.

Regional distribution of blood flow of dogs during graded dynamic exercise

1987 ◽  
Vol 63 (6) ◽  
pp. 2269-2277 ◽  
Author(s):  
T. I. Musch ◽  
D. B. Friedman ◽  
K. H. Pitetti ◽  
G. C. Haidet ◽  
J. Stray-Gundersen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Maximal Exercise ◽  
Regional Blood Flow ◽  
Regional Distribution ◽  
Work Load ◽  
Work Intensity ◽  
Semitendinosus Muscle ◽  
Blood Flows ◽  
Flow Response ◽  
Semimembranosus Muscle

The regional blood flow response to progressive treadmill exercise was measured with radioactive microspheres in 25 untrained mongrel dogs. Incremental increases in work intensity resulted in corresponding increases in blood flows to the gracilis, gastrocnemius, semimembranosus, and semitendinosus muscles of the hindlimb and to the heart. During maximal exercise, blood flow was greatest in the semimembranosus muscle and lowest in the semitendinosus muscle (342 and 134 ml–1.100 g tissue-1.min-1, respectively). Exercise produced a decrease in blood flow to the temporalis muscle, which was classified as nonlocomotive in function. Blood flows to the stomach, pancreas, and large intestine decreased at the lowest exercise work load and remained diminished throughout the continuum to maximal exercise. Blood flows to the small intestine and spleen were maintained during submaximal exercise but were reduced by 50% at maximal O2 consumption (VO2max). No changes in blood flows to the kidneys, adrenal glands, liver, and brain were found. These results demonstrate that 1) renal blood flow is maintained at resting levels during exercise in untrained dogs; 2) blood flow changes in the various organs of the splanchnic region of dogs during exercise are heterogeneous; and 3) blood flows to the working skeletal muscles of dogs progressively increase with increasing work loads up to VO2max.

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

1988 ◽  
Vol 255 (4) ◽  
pp. H953-H959
Author(s):  
T. Sakamoto ◽  
S. Shimazaki ◽  
W. W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Sciatic Nerve ◽  
Regional Blood Flow ◽  
Spinal Cord Blood Flow ◽  
Pentobarbital Sodium ◽  
Group A ◽  
Sciatic Nerves ◽  
Group B ◽  
Stimulation Of

[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.

Effect of neuropeptides released from sensory nerves on blood flow in the rat airway microcirculation

1992 ◽  
Vol 72 (4) ◽  
pp. 1563-1570 ◽  
Author(s):  
G. Piedimonte ◽  
J. I. Hoffman ◽  
W. K. Husseini ◽  
W. L. Hiser ◽  
J. A. Nadel
Keyword(s):  
Blood Flow ◽  
Substance P ◽  
Regional Blood Flow ◽  
Reference Sample ◽  
Left Ventricular ◽  
Sensory Nerves ◽  
Microvascular Blood Flow ◽  
Systemic Injection ◽  
Airway Mucosa ◽  
Stimulation Of

Stimulation of sensory nerves in the airway mucosa causes local release of the neuropeptides substance P and calcitonin gene-related peptide (CGRP). In this study we used a modification of the reference-sample microsphere technique to measure changes in regional blood flow and cardiac output distribution produced in the rat by substance P, CGRP, and capsaicin (a drug that releases endogenous neuropeptides from sensory nerves). Three sets of microspheres labeled with different radionuclides were injected into the left ventricle of anesthetized F344 rats before, immediately after, and 5 min after left ventricular injections of capsaicin, substance P, or CGRP. The reference blood sample was withdrawn from the abdominal aorta and was simultaneously replaced with 0.9% NaCl at 37 degrees C. We found that stimulation of sensory nerves with a low dose of capsaicin causes a large and selective increase in microvascular blood flow in the extrapulmonary airways. The effect of capsaicin is mimicked by systemic injection of substance P but not by CGRP, suggesting that substance P is the main agent of neurogenic vasodilation in rat airways.

Regional circulatory responses to hypocapnia and hypercapnia in bar-headed geese

1986 ◽  
Vol 250 (3) ◽  
pp. R499-R504 ◽  
Author(s):  
F. M. Faraci ◽  
M. R. Fedde
Keyword(s):  
Blood Flow ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Pectoral Muscle ◽  
Blood Flows ◽  
Arterial Blood ◽  
Blood Flow Reduction ◽  
Extreme Altitude ◽  
Anser Indicus ◽  
O2 Delivery

To investigate mechanisms that may allow birds to tolerate extreme high altitude (hypocapnic hypoxia), we examined the effects of severe hypocapnia and moderate hypercapnia on regional blood flow in bar-headed geese (Anser indicus), a species that flies at altitudes up to 9,000 m. Cerebral, coronary, and pectoral muscle blood flows were measured using radioactive microspheres, while arterial CO2 tension (PaCO2) was varied from 7 to 62 Torr in awake normoxic birds. Arterial blood pressure was not affected by hypocapnia but increased slightly during hypercapnia. Heart rate did not change during alterations in PaCO2. Severe hypocapnia did not significantly alter cerebral, coronary, or pectoral muscle blood flow. Hypercapnia markedly increased cerebral and coronary blood flow, but pectoral muscle blood flow was unaffected. The lack of a blood flow reduction during severe hypocapnia may represent an important adaptation in these birds, enabling them to increase O2 delivery to the heart and brain at extreme altitude despite the presence of a very low PaCO2.

Regional blood flow and capillary permeability in the ethylnitrosourea-induced rat glioma

1981 ◽  
Vol 55 (6) ◽  
pp. 922-928 ◽  
Author(s):  
Kazuo Yamada ◽  
Toru Hayakawa ◽  
Yukitaka Ushio ◽  
Norio Arita ◽  
Amami Kato ◽  
...  
Keyword(s):  
Blood Flow ◽  
Brain Tissue ◽  
Evans Blue ◽  
Capillary Permeability ◽  
Regional Blood Flow ◽  
Blue Staining ◽  
Content Type ◽  
Rat Glioma ◽  
Blood Flows ◽  
Diameter Reduction

✓ Regional cerebral blood flow and capillary permeability of rat brains bearing ethylnitrosourea-induced gliomas of various size were investigated with 14C-antipyrine autoradiography and Evans blue staining. In the small tumors (<2 mm in diameter), blood flow was uniformly reduced when compared to the adjacent brain. Even in tiny tumors (0.3 to 0.4 mm in diameter), reduction in blood flow was evident. In the medium (2 to 4 mm in diameter) and large (> 4 mm in diameter) tumors, the blood flow increased or decreased depending on the part of the tumor examined. The necrotic center and peripheral edge had low blood flows, whereas the viable portion adjacent to the necrotic center had high blood flows. Blood flow in the brain tissue adjacent to medium and large tumors was lower than control brain tissue, probably due to local edema. Leakage of intravenous Evans blue in the tissue was only evident in the large tumors with central necrosis. The present findings suggest that neovascularization of the tumor may occur when the tumor reaches a certain size, and leaky new vessels may be the cause of brain edema associated with tumor.

scholarly journals Regional blood flow response to orthostasis in patients with congestive heart failure

1983 ◽  
Vol 1 (6) ◽  
pp. 1391-1395 ◽  
Author(s):  
Steven R. Goldsmith ◽  
Gary S. Francis ◽  
T. Barry Levine ◽  
Jay N. Cohn
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Blood Flow ◽  
Regional Blood Flow ◽  
Blood Flow Response ◽  
Flow Response

The effects of artificial lung inflation on pulmonary blood flow and heart rate in the turtle Trachemys scripta.

1997 ◽  
Vol 200 (19) ◽  
pp. 2539-2545
Author(s):  
J Herman ◽  
T Wang ◽  
A W Smits ◽  
J W Hicks
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Lung Volume ◽  
Pulmonary Blood Flow ◽  
Trachemys Scripta ◽  
Spontaneous Ventilation ◽  
Lung Inflation ◽  
Cardiovascular Changes ◽  
Blood Flows ◽  
Stimulation Of

As for most ectothermic vertebrates, the breathing pattern of turtles is episodic, and pulmonary blood flow (Qpul) and heart rate (fH) normally increase several-fold during spontaneous ventilation. While some previous studies suggest that these cardiovascular changes are caused by stimulation of pulmonary stretch receptors (PSRs) during ventilation, it has been noted in other studies that blood flows often change prior to the initiation of breathing. Given the uncertainty regarding the role of PSRs in the regulation of central vascular blood flows, we examined the effect of manipulating lung volume (and therefore PSR stimulation) on blood flows and heart rate in the freshwater turtle Trachemys scripta. Turtles were instrumented with blood flow probes on the left aortic arch and the left pulmonary artery for measurements of blood flow, and catheters were inserted into both lungs for manipulation of lung volume. In both anaesthetized and fully recovered animals, reductions or increases in lung volume by withdrawal of lung gas or injection of air, N2, O2 or 10% CO2 (in room air) had no effect on blood flows. Furthermore, simulations of normal breathing bouts by withdrawal and injection of lung gas did not alter Qpul or fH. We conclude that stimulation of PSRs is not sufficient to elicit cardiovascular changes and that the large increase in Qpul and fH normally observed during spontaneous ventilation are probably caused by a simultaneous feedforward control of central origin.

Regional blood flow in conscious resting rats determined by microsphere distribution

1993 ◽  
Vol 74 (1) ◽  
pp. 203-210 ◽  
Author(s):  
I. Kuwahira ◽  
N. C. Gonzalez ◽  
N. Heisler ◽  
J. Piiper
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Regional Blood Flow ◽  
Sampling Technique ◽  
Organ Blood Flow ◽  
Sprague Dawley ◽  
Blood Flows ◽  
Hindlimb Muscles ◽  
Acclimation Period ◽  
The Difference

To determine organ blood flow in the resting state, a box was designed to keep conscious untrained rats minimally disturbed. Blood pressure, heart rate, and organ blood flow, determined by the microsphere distribution and reference sampling technique, were measured in 11 Sprague-Dawley rats. After an acclimation period, 15-microns-diameter microspheres labeled with 113Sn were infused into the ascending aorta, a reference blood sample was withdrawn from the caudal artery, and organ blood flows were computed according to standard procedures. The average values of heart rate (365 beats/min) and blood flow to the brain (45 ml.min-1.100 g-1) and hindlimb muscles (15 ml.min-1.100 g-1) were significantly lower than most values reported earlier, whereas splanchnic blood flow was significantly higher (106 ml.min-1.100 g-1). Blood flow to the soleus muscle, which is considered the most active for postural maintenance, was relatively high (99 ml.min-1.100 g-1). The combination of low skeletal muscle and high visceral blood flows observed in these experiments suggests a low sympathetic tone, which is consistent with the low level of circulating catecholamines also observed in this study. It is hypothesized that the difference between our present and previous results is a lower level of stress, attributable to a more complete acclimation to the experimental environment.

Vasodilation in skeletal muscle

1963 ◽  
Vol 204 (3) ◽  
pp. 461-466 ◽  
Author(s):  
Richard D. Jones ◽  
Robert M. Berne
Keyword(s):  
Blood Flow ◽  
Muscle Blood Flow ◽  
Aortic Pressure ◽  
Direct Stimulation ◽  
Nerve Section ◽  
Epinephrine Administration ◽  
Pressure Elevation ◽  
Blood Flow Increase ◽  
Sciatic Nerves ◽  
Stimulation Of

Blood flow was studied in dog hind-limb muscle isolated except for femoral and sciatic nerves. At constant perfusion pressure, elevation of aortic pressure produced by blood transfusion or intravenous epinephrine administration elicited a three- to fourfold increase in blood flow in perfused muscle. The blood flow increase evoked by epinephrine could be prevented by maintaining aortic pressure at control levels by means of a pressure compensator. Carotid artery occlusion had little effect on muscle blood flow whereas release of carotid occlusion produced marked increases. Cold or procaine block of the femoral or sciatic nerves resulted in little change in blood flow, whereas nerve section distal to the block produced large transient increases in flow. It is concluded that muscle blood flow increase after aortic pressure elevation is the result of active vasodilation and that increase in muscle blood flow after nerve section is due to stimulation of vasodilator fibers or direct stimulation of vascular smooth muscle by pressure changes produced by the twitch contraction associated with nerve section.

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