Lack of effect of peripheral nervous blockade on nocturnal fluctuations in lower-leg subcutaneous blood flow in man

1993 ◽  
Vol 84 (3) ◽  
pp. 297-304 ◽  
Author(s):  
J. H. Sindrup ◽  
L. J. Petersen ◽  
J. Kastrup ◽  
H. Wroblewski ◽  
J. K. Kristensen
Keyword(s):  
Blood Flow ◽  
Data Storage ◽  
Human Subjects ◽  
Lower Leg ◽  
Tissue Blood Flow ◽  
Storage Unit ◽  
Significant Difference ◽  
Blood Flow Increase ◽  
Subcutaneous Blood Flow ◽  
The Right

1. The local subcutaneous adipose tissue blood flow was measured simultaneously in the right and left lower legs of 10 normal human subjects under outpatient nocturnal conditions. The 133Xe-wash-out technique, portable CdTe(Cl) detectors and a portable data-storage unit were used for the measurement of blood flow. 2. The purpose of the study was to unveil the possible role of centrally controlled nerve fibres to the measurement area as mediators of a previously described nocturnal subcutaneous hyperaemia of 2 h duration. Therefore, before the sleeping period, a local nervous blockade was applied immediately proximal to the isotope depot on the right lower leg by the injection of approximately 15 ml of bupivacaine (5 mg/ml) subcutaneously. 3. Control experiments revealed blockade of the baroreceptor vasoconstrictor reflex activity 4 h after application of the local nervous blockade in three subjects examined. 4. Identical nocturnal isotope-wash-out curves were recorded from the two legs. Subcutaneous blood flow was found to increase significantly (P <0.0001) after approximately 1 h of sleep and the hyperaemia persisted for 2 h. 5. A significant positive correlation was detected between the latency periods from going to bed until the onset of the hyperaemia in the right and left lower legs (P <0.001, r = 0.95). 6. No significant difference could be detected between the relative blood flow increase during the hyperaemic phase in the right and left lower legs (P = 0.83). 7. It is concluded that the present data seem to rule out a central nervous factor(s) as the eliciting mechanism of the nocturnal subcutaneous hyperaemia. A circulating humoral factor(s) might be involved, although modification by local metabolic factors cannot be excluded. The possible physiological significance of the nocturnal hyperaemia is discussed.

Nocturnal variations in subcutaneous blood flow rate in lower leg of normal human subjects

1991 ◽  
Vol 260 (2) ◽  
pp. H480-H485 ◽  
Author(s):  
J. H. Sindrup ◽  
J. Kastrup ◽  
B. Jorgensen ◽  
J. Bulow ◽  
N. A. Lassen
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Human Subjects ◽  
Blood Flow Rate ◽  
Lower Leg ◽  
Tissue Blood Flow ◽  
Subcutaneous Blood Flow ◽  
Normal Human ◽  
Night Period ◽  
133Xe Washout

Subcutaneous adipose tissue blood flow rate was measured in the lower leg of 22 normal human subjects over 12- to 20-h ambulatory conditions. The 133Xe washout technique, portable CdTe(Cl) detectors, and a portable data storage unit were used. The tracer depot was applied on the medial aspect of the right lower leg 10 cm proximal to the malleolar level by means of the epicutaneous, atraumatic labeling technique. The change from upright to supine position from day 1 in the beginning of the night period elicited an instantaneous blood flow rate increment of 30-40% in accordance with a decrease in central and local postural sympathetic vasoconstrictor activity. During sleep, characteristic variations in subcutaneous blood flow were disclosed. The 133Xe washout curve could be divided into three segments with significantly different slopes. Approximately 90 min after the subject went to sleep, an additional blood flow rate increment of considerable magnitude was observed. The mean increase was 84%, but in several cases a greater than 200% increment was measured (maximum 244%). The intra-individual coefficient of variation for the nocturnal blood flow response was in triplicate measurements 25% (n = 9). The hyperemic phase lasted approximately 100 min after which the blood flow rate returned to the level measured at the beginning of the night period. The blood flow rates measured on the second day did not differ from those on the first day. Control measurements performed under similar thermal conditions, but with the subjects kept awake, did not reveal any hyperemic phases. This points toward changes in cardiovascular regulatory mechanisms during sleep.(ABSTRACT TRUNCATED AT 250 WORDS)

Nocturnal variations in lower-leg subcutaneous blood flow in paraplegic men

1992 ◽  
Vol 82 (1) ◽  
pp. 47-54 ◽  
Author(s):  
J. H. Sindrup ◽  
H. Wroblewski ◽  
J. Kastrup ◽  
F. Biering-Sørensen
Keyword(s):  
Blood Flow ◽  
Lower Leg ◽  
Tissue Blood Flow ◽  
Peripheral Blood Flow ◽  
Adipose Tissue Blood Flow ◽  
Flow Phase ◽  
Hyperaemic Response ◽  
Subcutaneous Blood Flow ◽  
The Right ◽  
Subcutaneous Adipose

1. Lower-leg subcutaneous adipose tissue blood flow rates were measured over 12-20 h under ambulatory conditions by means of the 133Xe-washout technique in nine paraplegic men, all with complete spinal cord lesions at or below the Th 6 level, and in nine age-matched healthy men. Portable CdTe(Cl) detectors and datastorage units were used. 2. The central and local sympathetic vasoconstrictive activity at the lower leg was measured under laboratory conditions by means of the l33Xe-washout technique and a stationary NaI(TI) detector system. 3. The paraplegic men were found to have intact central and local sympathetic vasoconstrictive activity in their lower legs. Moreover, they all had a nocturnal hyperaemic blood flow phase of the same magnitude and duration as the control subjects. 4. The possibility that the somaesthetic nerves play a role in the hyperaemic response could be excluded, as all the paraplegic men suffered from complete lower-leg somaesthetic denervation. 5. A significant correlation was found between the time of going to bed and the nightly hyperaemic response in the right and left lower legs (P < 0.01). 6. It is concluded that the present data are in accordance with the concept of a central nervous or humoral elicitation of nocturnal hyperaemia, although local metabolic and other factors might participate as well. Paraplegic men have an intact regulation of the postural and nocturnal changes in peripheral blood flow whether of central sympathetic or humoral origin.

Effect of spaceflight on the subcutaneous venoarteriolar reflex in the human lower leg

2007 ◽  
Vol 103 (3) ◽  
pp. 959-962 ◽  
Author(s):  
Anders Gabrielsen ◽  
Peter Norsk
Keyword(s):  
Blood Flow ◽  
Knee Joint ◽  
Ankle Joint ◽  
Lower Leg ◽  
Statistical Significant Difference ◽  
Significant Difference ◽  
The Everyday ◽  
Decrease Blood Flow ◽  
Subcutaneous Blood Flow

Whenever the legs are lowered in humans, a venoarteriolar reflex is activated by the hydrostatic distension of the venules. Through local axon reflexes, the adjacent arterioles are contracted to decrease blood flow and prevent formation of edema. Because the venoarteriolar reflex is activated by gravity, we tested the hypothesis that long-term weightlessness would attenuate it. The reduction in subcutaneous blood flow was measured by the 133Xe washout technique just proximal to the ankle joint in dependent lower legs of eight supine astronauts, where the knee joint was passively bent by 90°. The measurements were conducted before spaceflight and 3–6 h on landing following 4–6.5 mo in space. Activation of the venoarteriolar reflex reduced subcutaneous blood flow by 37 ± 9% ( P = 0.016) before flight and by 64 ± 8% ( P < 0.001) following landing with no statistical significant difference between the two reductions ( P = 0.062). Therefore, our results show that the venoarteriolar reflex is not attenuated by weightlessness and therefore does not need the everyday stimulus of gravity to maintain efficiency.

Non-Newtonian Blood Flow in the Right Coronary Artery

2004 ◽  
Author(s):  
Narcisse A. N’Dri ◽  
Don P. Giddens
Keyword(s):  
Blood Flow ◽  
Power Law ◽  
Human Subjects ◽  
Flow Behavior ◽  
Circulatory System ◽  
Arterial Grafts ◽  
Commercial Code ◽  
Significant Difference ◽  
Time Average ◽  
The Right

Understanding blood flow in the circulatory system and how it affects intimal thickening is important with respect to atherogenesis and also for the design of vascular treatment devices such as stents and arterial grafts. While the assumption of Newtonian blood flow in large arteries is widely accepted by many investigators, questions remain unanswered for blood flow in the coronaries. In this study we investigate Non-Newtonian blood flow behavior in both the right and the left coronaries. We use a commercial code (FIDAP) to compare the Newtonian model to four Non-Newtonian models (Power law, Casson, Carreau and Quemada models) widely used in the literature. The coronary geometries were reconstructed from MRI images of human subjects. We found a significant difference in time average WSS between the power law and the Newtonian models. Also a difference in time average WSS is observed for the Quemada model. On the other hand, No significant difference is observed for the Newtonian, Casson and Carreau models.

MECHANISMS OF PERIPHERAL TISSUE BLOOD FLOW INFLUENCED BY HIGH SALT DIET IN YOUNG HEALTHY FEMALE HUMAN SUBJECTS

2011 ◽  
Vol 29 ◽  
pp. e197
Author(s):  
A. Cavka ◽  
I. Grizelj ◽  
B. Jelakovic ◽  
J. H. Lombard ◽  
I. Mihaljevic ◽  
...  
Keyword(s):  
Blood Flow ◽  
Human Subjects ◽  
High Salt ◽  
Peripheral Tissue ◽  
Tissue Blood Flow ◽  
High Salt Diet ◽  
Salt Diet ◽  
Healthy Female

scholarly journals Evaluation of the marginal gingival health using laser doppler flowmetry

2006 ◽  
Vol 17 (3) ◽  
pp. 219-222 ◽  
Author(s):  
Hakan Develioglu ◽  
Bülent Kesim ◽  
Aykut Tuncel
Keyword(s):  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Plaque Index ◽  
Tissue Blood Flow ◽  
Doppler Flowmetry ◽  
Gingival Health ◽  
Significant Difference ◽  
Clinical Indices ◽  
And Control

The purposes of this study were to compare the gingival blood flow (GBF) in test sites (teeth retaining fixed partial dentures) and control sites (contralateral natural teeth) and investigate whether there is any relationship between clinical indices and GBF values. Twelve healthy subjects (6 females and 6 males) aged 20 to 54 years were enrolled this study. The GBF was measured from the middle point of the marginal gingiva in the test and control sites using laser Doppler flowmetry (LDF). Additionally, plaque index, gingival index and probing depth measurements were recorded. Statistically significant difference (p<0.05) was found between the test and control sites for marginal GBF. In contrast, no significant difference (p>0.05) was found between test and control sites with respect to the clinical indices, except for plaque index. The findings of this study suggest that there is a significant relation between resin-bonded fixed partial dentures with margins located subgingivally and marginal GBF. Clinical indices are helpful to collect information about the clinical health status of gingival tissues, but GBF is a good tool to measure gingival tissue blood flow and assess periodontal health. In conclusion, laser Doppler flowmetry can be used together with clinical indices to evaluate the marginal gingival health.

Nocturnal variations in human lower leg subcutaneous blood flow related to sleep stages

1992 ◽  
Vol 73 (4) ◽  
pp. 1246-1252 ◽  
Author(s):  
J. H. Sindrup ◽  
J. Kastrup ◽  
P. L. Madsen ◽  
H. Christensen ◽  
B. Jorgensen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
First Episode ◽  
Tissue Blood Flow ◽  
Sleep Stages ◽  
Deep Sleep ◽  
Arterial Blood ◽  
Subcutaneous Blood Flow ◽  
The Moment

Nocturnal subcutaneous adipose tissue blood flow rate was measured in the lower legs of 10 normal human subjects together with systemic arterial blood pressure, heart rate, and registration of sleep stages under ambulatory conditions. The 133Xe washout technique, portable CdTe(Cl) detectors, and a portable data storage unit were used for measurement of blood flow rates. The sleep recordings were performed with a portable computerized sleep analysis system. In accordance with the results of previous studies, a hyperemic blood flow rate phase (mean increase 140%) for 100 min was observed approximately 60 min after the subjects went to bed. The moment of onset of the hyperemic phase was closely related to the moment of onset of the first episode of deep sleep (stages 3 and 4). There was a significant (P < 0.01) overrepresentation of deep sleep in the hyperemic phase compared with adjacent phases, and rapid-eye-movement sleep predominantly occurred in the latter part of the night, when the subcutaneous blood flow rate was stable. The results of the present study are in accordance with current theories of the interrelationship between the thermoregulatory and the arousal state control systems and, thus, might suggest that the nightly subcutaneous hyperemia represents a thermoregulatory effector mechanism.

Effect of active muscle mass during ischemic exercise on peak lower leg vascular conductance

2005 ◽  
Vol 98 (3) ◽  
pp. 765-771 ◽  
Author(s):  
Aaron J. Polichnowski ◽  
Ellen K. Heyer ◽  
Alexander V. Ng
Keyword(s):  
Blood Flow ◽  
Muscle Mass ◽  
Plantar Flexion ◽  
Arterial Occlusion ◽  
Venous Occlusion ◽  
Lower Leg ◽  
Isokinetic Dynamometer ◽  
Active Muscle ◽  
Vascular Conductance ◽  
The Right

Uncertainty exists as to whether a period of passive arterial occlusion (PAO) or ischemic exercise (IE) results in peak lower leg vascular conductance (LVC). This uncertainty is due to the different body positions, active muscle mass, and occlusion times used for PAO or IE. The purpose of this study was to examine whether 10 min of PAO elicits a similar LVC compared with ischemic dorsiflexion (IDF), ischemic plantar flexion (IPF), and ischemic plantar-dorsiflexion (IPDF). Ten subjects (5 women, 27 ± 9 yr, 68 ± 3 kg) were studied on 3 days over 1 wk in a semireclined position with the right foot attached to an isokinetic dynamometer. Mean arterial pressure (Finapres) and lower leg blood flow (LBF, venous occlusion plethysmography) were measured at rest and after PAO and IE. PAO was administered randomly on 1 of the 3 days and before IE. IE protocols consisted of maximal isokinetic dorsiflexion and/or plantar flexion at 120 and 60°/s, respectively. In a second experiment, an additional eight subjects (4 women, 29 ± 12 yr, 77 ± 12 kg) were studied to examine the effect of isokinetic speed during IDF on peak LBF and LVC. Peak LVC (ml·min−1·100 ml−1·mmHg−1) was similar among IPF (0.590 ± 0.16), IPDF (0.532 ± 0.17), and PAO (0.511 ± 0.18), and significantly lower after IDF (0.334 ± 0.15). No differences in peak LBF and LVC were observed after IDF using different isokinetic speeds. We conclude that 10 min of PAO, IPF, and IPDF performed in a similar posture are adequate stimuli to elicit peak LVC.

Evidence for a dorso-medial parietal system involved in mental transformations of the body

1996 ◽  
Vol 76 (3) ◽  
pp. 2042-2048 ◽  
Author(s):  
E. Bonda ◽  
S. Frey ◽  
M. Petrides
Keyword(s):  
Blood Flow ◽  
Parietal Cortex ◽  
Human Subjects ◽  
Body Position ◽  
The Body ◽  
Right Hand ◽  
Positron Emission ◽  
Superior Parietal Cortex ◽  
The Right ◽  
Mental Transformations

1. The neural systems underlying body-space mental representation were studied by measuring changes in regional cerebral blood flow (CBF) with positron emission tomography in human subjects. 2. The experimental paradigm involved identification of the left or the right hand of the experimenter presented in different orientations or the palm of the subject's right hand. The subjects were required to decide whether it was the left or the right hand that was presented. To perform this task, the subjects had to move mentally the position of their own arm to adopt that of the experimenter's arm. The control condition involved the same type of tactual stimulation without the requirement of mental transformations of the subject's body position. The distribution of CBF was measured by means of the water bolus H2(15)O methodology during the performance of these tasks. 3. Comparison of the distribution of CBF between the experimental and control tasks was carried out to reveal changes specific to the mental transformations of the subject's body. Significant blood flow increases were observed in the caudal superior parietal cortex, including the intraparietal sulcus, and the adjacent medial parietal cortex. These findings demonstrated that there is a dorsomedially directed parietal system underlying mental transformations of the body in interactive relation with external space.

Determinants for outcome of hypoplastic right ventricle with duct-dependent pulmonary blood flow presenting in the neonatal period

1992 ◽  
Vol 2 (4) ◽  
pp. 377-381 ◽  
Author(s):  
Michael L. Rigby ◽  
Micelia Salgado ◽  
Celia Silva
Keyword(s):  
Blood Flow ◽  
Right Ventricle ◽  
Pulmonary Blood Flow ◽  
Pulmonary Valve ◽  
Pulmonary Atresia ◽  
Cross Sectional ◽  
Mitral Valves ◽  
Significant Difference ◽  
The Right ◽  
Pulmonary Valvar Stenosis

SummaryA retrospective study was undertaken of patients with hypoplastic right ventricles, either with pulmonary atresia and intact ventricular septum or critical pulmonary valvar stenosis, and duct-dependent pulmonary blood flow who were investigated at the Royal Brompton Hospital between January 1976 and December 1990. The diagnosis was made on the basis of at least one diagnostic method (cross-sectional echocardiography, cardiac catheterization and angiography, or autopsy). Of the patients, 56 (82%) were found to have an imperforate pulmonary valve or infundibulum (pulmonary atresia), while 12(18%) had critical pulmonary valvar stenosis. The ratio of the diameters of the tricuspid and mitral valvar orifices was measured angiographically during diastole, and the right ventricle was analyzed according to the presence or overgrowth of the inlet, apical trabecular and outlet components. A correlation was made between the severity of the disease and the outcome. The overall mortality was 53% when those not undergoing any surgery were excluded, and significant differences were found between the group dying and those who survived. The incremental risk factors for death were a ratio between the diameter of the tricuspid and mitral valves of less than 0.6; the presence of fistulous communications with the coronary arteries; and obliteration of the apical trabecular component of the right ventricle. There was no significant difference between the group with pulmonary valvar atresia and the group with critical stenosis of the pulmonary valve.

Sign in / Sign up

Export Citation Format

Share Document