Hand circulation in the cold of Lapps and North Norwegian fishermen

1960 ◽  
Vol 15 (4) ◽  
pp. 654-658 ◽  
Author(s):  
J. Krog ◽  
B. Folkow ◽  
R. H. Fox ◽  
K. Lange Andersen
Keyword(s):  
Blood Flow ◽  
Thermal Environment ◽  
Venous Occlusion ◽  
Vascular Response ◽  
General Process ◽  
Blood Flows ◽  
Control Subjects ◽  
The Difference ◽  
Response To Temperature ◽  
Habituation To Cold

The hand blood flows of Norwegian Lapps and North Norwegian fishermen were compared with those of a group of control subjects to determine whether habituation to cold alters the local vascular response. Blood flow was measured using venous occlusion plethysmographs with local temperatures of 40°, 20°, 10°C and a few degrees above zero. In further experiments using Dewar-flask calorimeters, the rate of heat elimination and rapidity of onset of the cold vasodilatation response on immersing the hand in water at 0°C were also recorded. The subjects were kept warm in order to remove as far as possible the effects of differing degrees of vasoconstrictor fiber activity. The onset of the cold vasodilatation was found to be more rapid in the cold-habituated subjects than in the control subjects. The levels of hand blood flow were, however, the same in all three groups of subjects, implying that habituation to cold does not alter the local vascular response to temperature. It is suggested that the difference reported by other workers in similar studies are probably found only when subjects examined are partially vasoconstricted, and reflect a more general process of adaptation to cold which results in a reduced vasoconstrictor fiber activity on exposure to a given thermal environment. Submitted on August 19, 1959

Maximal vascular leg conductance in trained and untrained men

1987 ◽  
Vol 62 (2) ◽  
pp. 606-610 ◽  
Author(s):  
P. G. Snell ◽  
W. H. Martin ◽  
J. C. Buckey ◽  
C. G. Blomqvist
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Reactive Hyperemia ◽  
Venous Occlusion ◽  
Vascular Conductance ◽  
Blood Flows ◽  
Arterial Blood ◽  
Sedentary Subjects

Lower leg blood flow and vascular conductance were studied and related to maximal oxygen uptake in 15 sedentary men (28.5 +/- 1.2 yr, mean +/- SE) and 11 endurance-trained men (30.5 +/- 2.0 yr). Blood flows were obtained at rest and during reactive hyperemia produced by ischemic exercise to fatigue. Vascular conductance was computed from blood flow measured by venous occlusion plethysmography, and mean arterial blood pressure was determined by auscultation of the brachial artery. Resting blood flow and mean arterial pressure were similar in both groups (combined mean, 3.0 ml X min-1 X 100 ml-1 and 88.2 mmHg). After ischemic exercise, blood flows were 29- and 19-fold higher (P less than 0.001) than rest in trained (83.3 +/- 3.8 ml X min-1 X 100 ml-1) and sedentary subjects (61.5 +/- 2.3 ml X min-1 X 100 ml-1), respectively. Blood pressure and heart rate were only slightly elevated in both groups. Maximal vascular conductance was significantly higher (P less than 0.001) in the trained compared with the sedentary subjects. The correlation coefficients for maximal oxygen uptake vs. vascular conductance were 0.81 (trained) and 0.45 (sedentary). These data suggest that physical training increases the capacity for vasodilation in active limbs and also enables the trained individual to utilize a larger fraction of maximal vascular conductance than the sedentary subject.

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.

Forearm Vascular Response to Nitric Oxide and Calcitonin Gene- Related Peptide: Comparison between Migraine Patients and Control Subjects

Cephalalgia ◽  
2006 ◽  
Vol 26 (1) ◽  
pp. 56-63 ◽  
Author(s):  
JNJM de Hoon ◽  
P Smits ◽  
J Troost ◽  
HAJ Struijker-Boudier ◽  
LMAB Van Bortel
Keyword(s):  
Nitric Oxide ◽  
Vascular Function ◽  
Venous Occlusion ◽  
Calcitonin Gene Related Peptide ◽  
Vascular Response ◽  
No Donor ◽  
Related Peptide ◽  
Control Subjects ◽  
Calcitonin Gene ◽  
Endogenous Release

The forearm vascular response to nitric oxide (NO) and calcitonin gene-related peptide (CGRP) was investigated in 10 migraine patients and 10 matched control subjects. Changes in forearm blood flow (FBF) during intrabrachial infusion of: (i) serotonin (releasing endogenous NO), (ii) sodium nitroprusside (SNP, exogenous NO-donor), and (iii) CGRP were measured using venous occlusion plethysmography. Flow-mediated dilation (FMD) of the brachial artery, a measure for the endogenous release of NO reactive to occlusion, was measured using ultrasound and expressed as percentage change vs. baseline diameter. FBF ratio (i.e. FBF in the infused over the control arm) at baseline (1.1 ± 0.1) did not differ between both populations. Serotonin, SNP and CGRP induced a dose-dependent increase ( P < 0.001) in FBF ratio in controls (to 2.8 ± 0.3, 6.7 ± 1.4 and 6.9 ± 1.2 at the highest dose, respectively) and migraineurs (2.5 ± 0.4, 5.6 ± 0.8 and 6.5 ± 1.3, respectively); these ratios did not differ between both groups. FMD was comparable in control subjects (5.8 ± 1%) and migraine patients (5.2 ± 1%). Based on the forearm vascular response to NO and CGRP, migraine patients do not display generalized changes in vascular function.

Accuracy of Ultrasonic-Measurement-Integrated Simulation for Three-Dimensional Blood Flow in Aneurysmal Aorta

2007 ◽  
Author(s):  
K. Funamoto ◽  
T. Hayase ◽  
Y. Saijo ◽  
T. Yambe
Keyword(s):  
Boundary Condition ◽  
Blood Flow ◽  
Three Dimensional ◽  
Optimal Estimation ◽  
Ultrasonic Measurement ◽  
Integrated Simulation ◽  
Blood Flows ◽  
Standard Solution ◽  
The Difference ◽  
Grid Points

The Ultrasonic-Measurement-Integrated (UMI) simulation, in which feedback signals proportional to the optimal estimation of the difference in velocity vector against real blood flow obtained by Doppler velocities are applied at grid points in the feedback domain, has been developed to reproduce complicated hemodynamics. This paper evaluates UMI simulation for three-dimensional unsteady blood flow in aneurysmal aorta. We performed a numerical experiment of UMI simulation with an unsteady standard solution of the three-dimensional blood flow in an aneurysmal aorta with a realistic boundary condition. The UMI simulation was performed with an inaccurate boundary condition and various feedback arrangements assuming the acquisition of Doppler velocities in the aneurysmal domain or feedback domain. The application of feedback made the computational result approach to the standard solution, so that UMI simulation estimated the hemodynamic stresses more correctly than the ordinary simulation. Hence, UMI simulation of real blood flows will bring significant benefits for the clinical diagnosis and treatment of circulatory diseases.

Body temperature control of rat tail blood flow

1983 ◽  
Vol 245 (3) ◽  
pp. R426-R432 ◽  
Author(s):  
E. R. Raman ◽  
M. F. Roberts ◽  
V. J. Vanhuyse
Keyword(s):  
Blood Flow ◽  
Heat Exchange ◽  
Body Temperature ◽  
Heat Flow ◽  
Thermal Conductance ◽  
Venous Occlusion ◽  
Albino Rats ◽  
Blood Flows ◽  
Rat Tail ◽  
Tail Blood

Tail blood flow (BF) and heat flow (HF) were measured in five albino rats during transients in rectal temperature (Tre) caused by body heating at rest. During heating, tail temperature (Tt) was kept at 15, 20, 25, 30, 35, or 42 degrees C by enclosing the tail in a water-perfused tube. Thermal conductance (K) was computed as HF/(Tre-Tt). BF was measured by venous occlusion plethysmography. Heating caused a rise in Tre that was accompanied by proportional increases in both K and BF. The ratio R = K/BF represents conductance per unit BF and reflects the amount of heat exchange for a given BF. R can thus be used to estimate the distribution of BF within the tail. R was independent of Tre at all Tt, indicating that BF distribution is controlled by the tail. R was low at low Tt and rose at higher Tt. This suggests that at low Tt, blood flows primarily in central veins of the tail and at higher Tt blood flows in peripheral tail veins.

Increased Cutaneous Vasoreactivity to Cold in Anorexia Nervosa

1981 ◽  
Vol 61 (5) ◽  
pp. 559-567 ◽  
Author(s):  
P. Luck ◽  
A. Wakeling
Keyword(s):  
Anorexia Nervosa ◽  
Peripheral Circulation ◽  
Venous Occlusion ◽  
Male Control ◽  
Blood Flows ◽  
Control Subjects ◽  
Warm Environment ◽  
The Mean ◽  
Thermal Stimuli ◽  
Female Control

1. Hand blood flows in healthy young men and women and in patients with anorexia nervosa were measured in a warm environment by using venous occlusion plethysmography. The mean core temperature of each of the three groups was similar, but the male control subjects and the anorexic patients had significantly higher peripheral blood flows than the female control subjects. 2. Blood flows were determined in the hand after 6 min localized cooling of it at varying temperatures. The female control subjects and the majority of the anorexic patients had blood flows which were similar for a given temperature, and lay between the higher values of the male control subjects and the low values of the remaining anorexic patients. 3. Those patients whose vascular responses to cold were exaggerated were characterized clinically by severe and persistent signs of ischaemia of the extremities during subsequent rehabilitation, unlike the majority of patients whose peripheral circulation rapidly improved. 4. Cold thermal stimuli evoked marked falls in blood flow of the contralateral (non-cooled) hand in the male and female control subjects, but these responses were attenuated or absent in the anorexic patients. An altered set-point for vasomotor thermoregulation in anorexia nervosa could explain these findings. 5. Plasma and whole-blood viscosity and erythrocyte deformability measured in a sample of the patients studied were similar to the values obtained from a sample of the control subjects. 6. It was concluded that the cutaneous vasoconstrictor responses to cold in the majority of the anorexic patients studied were quantitatively normal. The mechanism of the response, however, was different in that the vessels themselves were unusually reactive to cold. Increased cuteneous vasoreactivity to cold could contribute to the severe peripheral hypoperfusion observed in some anorexic patients.

Enhanced maximal metabolic vasodilatation in the dominant forearms of tennis players

1986 ◽  
Vol 61 (2) ◽  
pp. 673-678 ◽  
Author(s):  
L. I. Sinoway ◽  
T. I. Musch ◽  
J. R. Minotti ◽  
R. Zelis
Keyword(s):  
Blood Flow ◽  
Forearm Blood Flow ◽  
Arterial Occlusion ◽  
Study Groups ◽  
Venous Occlusion ◽  
Control Group ◽  
Tennis Players ◽  
Blood Flows ◽  
Metabolic Vasodilation ◽  
Adaptation To Exercise

In an effort to evaluate potential peripheral adaptations to training, maximal metabolic vasodilation was studied in the dominant and nondominant forearms of six tennis players and six control subjects. Maximal metabolic vasodilation was defined as the peak forearm blood flow measured after release of arterial occlusion, the reactive hyperemic blood flow (RHBF). Two ischemic stimuli were employed in each subject: 5 min of arterial occlusion (RHBF5) and 5 min of arterial occlusion coupled with 1 min of ischemic exercise (RHBF5ex). RHBF and resting forearm blood flows were measured using venous occlusion strain-gauge plethysmography (ml X min-1 X 100 ml-1). Resting forearm blood flows were similar in both arms of both groups. RHBF5ex was similar in both arms of our control group (dominant, 40.8 +/- 1.2 vs. nondominant, 40.9 +/- 2.1). However, RHBF5ex was 42% higher in the dominant than in the nondominant forearms of our tennis player population (dominant, 48.7 +/- 4.0 vs. nondominant, 34.4 +/- 3.4; P less than 0.05). This intraindividual difference in peak forearm blood flows was not secondary to improved systemic conditioning since the maximal O2 consumptions in the two study groups were similar (controls, 45.4 +/- 3.9 vs. tennis players, 46.1 +/- 1.7). These findings suggest a primary peripheral cardiovascular adaptation to exercise training in the dominant forearms of the tennis players resulting in a greater maximal vasodilatation.

Chemodenervation does not alter cerebrovascular response to hypoxic hypoxia

1989 ◽  
Vol 257 (5) ◽  
pp. H1413-H1418 ◽  
Author(s):  
M. Miyabe ◽  
M. D. Jones ◽  
R. C. Koehler ◽  
R. J. Traystman
Keyword(s):  
Blood Flow ◽  
Vascular Tone ◽  
Hypoxic Hypoxia ◽  
Blood Flows ◽  
Sagittal Sinus ◽  
Radioactive Microsphere ◽  
Sham Surgery ◽  
Regional Brain ◽  
Cervical Vagotomy ◽  
The Difference

We tested the hypothesis that sinoaortic chemodenervation would alter the increase in cerebral blood flow (CBF) during isocapnic hypoxic hypoxia in 1- to 7-day-old lambs. Lambs were anesthetized with pentobarbital and studied during moderate (arterial O2 content [CaO2] = 10 vol/100 ml) and severe (CaO2 = 6 vol/100 ml) hypoxic hypoxia. Regional brain blood flows were measured with the radioactive microsphere technique. Cerebral oxygen consumption (CMRO2) was calculated as the product of forebrain blood flow and the difference in oxygen contents between arterial and sagittal sinus blood. Lambs were then subjected to either sham surgery (n = 6) or to carotid chemodenervation and cervical vagotomy (n = 6). Chemodenervation was verified by abolition of the transient increase in blood pressure after intravenous injection of sodium cyanide in intact subjects. Neither sham surgery nor chemodenervation had an effect on CMRO2 or CBF during hypoxic hypoxia. These data thus do not support the hypothesis that arterial chemoreceptors play any substantial role in the regulation of cerebral vascular tone during hypoxic hypoxia in the 1- to 7-day-old anesthetized lamb.

Automated limb blood flow plethysmograph

1983 ◽  
Vol 244 (3) ◽  
pp. H413-H416
Author(s):  
R. R. Marcus ◽  
S. M. Horvath
Keyword(s):  
Blood Flow ◽  
Real Time ◽  
Cuff Pressure ◽  
Calculated Data ◽  
User Interaction ◽  
Venous Occlusion ◽  
Limb Blood Flow ◽  
Graphic Display ◽  
Computer Terminal ◽  
Blood Flows

An automated limb blood flow plethysmograph has been developed and interfaced to a PDP-11/60 computer. This system automatically inflates blood pressure cuffs, calibrates strain gauges, provides real-time display of limb circumference changes, and provides digital output of limb blood flow and real-time graphic display of cuff pressure. The system has been designed to require a minimum amount of user interaction by providing automatic calibration in situ, which is initiated by depressing a switch, and automatic venous cuff inflation, which initiates computer analysis of blood flow data. Digital and graphic display of blood flow is provided on a computer terminal 12 s after the start of venous occlusion. All raw data are stored on a disk for optional postexperiment analysis, which enables each blood flow curve to be graphically displayed and reanalyzed under user control. Calculated data are stored on a disk for output to a line printer at the conclusion of an experiment. A trend plot of all analyzed blood flows can be displayed on a computer terminal anytime during an experiment.

Measurement by Venous Occlusion Plethysmography of Blood Flow through Surgically Created Arteriovenous Fistulae in the Human Forearm

1976 ◽  
Vol 50 (1) ◽  
pp. 43-49
Author(s):  
W. F. M. Wallace ◽  
J. P. Jamison
Keyword(s):  
Blood Flow ◽  
Arterial Occlusion ◽  
Venous Occlusion ◽  
Limited Range ◽  
Similar Amount ◽  
Absolute Value ◽  
Human Forearm ◽  
Flow Through ◽  
The Difference ◽  
Two Sides

1. Plethysmographs containing the hand plus forearm were used to measure blood flow in patients with a surgically created arteriovenous fistula in one forearm. 2. Apparent flow rate was stable over a limited range of collecting pressures; the absolute value of these pressures varied from patient to patient. 3. After arterial occlusion, blood flow increased by a similar amount on the normal side and on the side with the fistula. 4. Occlusion of fistular flow produced no significant change in heart rate. 5. Fistular flow, estimated as the difference between flow on the two sides, averaged 525 ml/min in seventeen patients.

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