Doppler Characterization of the Immediate Blood Flow Velocity Pattern after Release of Prolonged Venous Occlusion of the Forearm

1989 ◽  
Vol 77 (1) ◽  
pp. 11-12 ◽  
Author(s):  
J. N. W. West ◽  
M. S. Salih ◽  
W. A. Littler
Keyword(s):  
Blood Flow ◽  
Venous Occlusion ◽  
Short Term ◽  
Velocity Pattern ◽  
Flow Response ◽  
Resistance Vessels ◽  
Capacitance Vessels ◽  
Doppler Techniques ◽  
Flow Through

1. There is a biphasic flow response measured plethysmographically after release of prolonged venous occlusion of the forearm. 2. The response consists of an early, vasodilatory, increase in flow and is followed by a decrease in flow relative to control, thought to be mediated by myogenic contraction of resistance vessels. 3. Methodological constraints with the technique of forearm plethysmography have to date precluded an individual beat-by-beat examination of this response, in particular for resolving the question of the immediate flow pattern after release of venous occlusion. It has been suggested by Caro, Foley & Sudlow [Journal of Physiology (London) (1970), 207, 257–269] that there is a delay of up to five systolic beats before vasodilatation takes place, leading to their suggestion that the vasodilatation is passive and secondary to an increased flow through emptied capacitance vessels. 4. The introduction of peripheral Doppler techniques has led us to re-examine this response in an attempt to define short-term resistance vessel behaviour on a beat-by-beat basis. 5. Our data confirmed the hypothesis of Caro, Foley & Sudlow [Journal of Physiology (London) (1970), 207, 257–269] that there is a constant and definite latency preceding the onset of vasodilatory flow, as reflected by changes in Doppler velocities.

scholarly journals Characterization of the Skeletal Muscle Microvascular Blood Flow Response to Tissue CO 2 Perturbations using a Gas Exchange Chamber

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Meaghan McCarthy ◽  
Meghan Kiley ◽  
Gaylene Russell McEvoy ◽  
Brenda Wells ◽  
Graham Fraser
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Gas Exchange ◽  
Microvascular Blood Flow ◽  
Blood Flow Response ◽  
Flow Response

Measurement of the cutaneous circulation

1965 ◽  
Vol 20 (4) ◽  
pp. 696-702 ◽  
Author(s):  
Harry M. Wright
Keyword(s):  
Blood Flow ◽  
Skin Temperature ◽  
Circulatory Arrest ◽  
Thermal Conductance ◽  
Venous Occlusion ◽  
Indirect Methods ◽  
Blood Content ◽  
Heating And Cooling ◽  
Flow Through ◽  
Cutaneous Circulation

Relationships between four commonly used indirect methods for study of the cutaneous circulation in intact, unanesthetized man were examined. Skin temperature, thermal conductance, volume plethysmography and the light absorption of the skin (as related to hemoglobin content) were simultaneously recorded on the upper extremities of normal young men as blood flow and blood content of the skin were changed by circulatory arrest, venous occlusion, indirect heating and cooling, and changes in position. Skin temperature and thermal conductance changed along parallel courses as blood flow was changed, while finger volume and reflectance of the skin to light of wavelength 550 mμ both changed in expected directions although along different courses, following passive congestion and de-congestion and changes in level of the hand relative to the heart. The advantages, disadvantages, and limitations of each of the methods in the study of cutaneous circulation in man are discussed and compared. measurement of circulation of skin; methods for measurement of cutaneous circulation; blood flow through skin; blood content of skin; skin Submitted on March 12, 1964

scholarly journals Parathyroid Hormone's Acute Effect on Vasodilatory Function

2010 ◽  
Vol 3 ◽  
pp. CMED.S4650 ◽  
Author(s):  
P. Farahnak ◽  
L. Lind ◽  
K. Mattala ◽  
I-L. Nilsson
Keyword(s):  
Cardiovascular Disease ◽  
Blood Flow ◽  
Healthy Subjects ◽  
Forearm Blood Flow ◽  
Acute Effect ◽  
Venous Occlusion ◽  
Arterial Infusion ◽  
Resistance Vessels ◽  
Vasodilatory Function ◽  
Pth Level

Parathyroid hormone (PTH) seems to affect the risk of cardiovascular disease. The aim of the present study was to investigate PTH's acute effect on endothelial vasodilatory function in forearm resistance vessels. Ten healthy subjects underwent forearm venous occlusion plethysmography. We measured forearm blood flow at baseline and at a stable, locally increased PTH level after intra-arterial infusion of metacholine and nitroprusside. The contralateral arm served as a control. Ionized calcium (Ca++) and PTH values were normal in all subjects at baseline (1.26 ± 0.02 mM/L, 3.6 ± 1.2 pM/L). After 30 minutes of PTH infusion, the PTH level increased in the active arm (13.8 ± 4.0 pM/L P < 0.01), while the Ca++ level was unchanged (1.25 ± 0.04; mM/L). Both the PTH and the Ca++ level in the contralateral arm remained unchanged, which indicates no systemic influence. The endothelial-dependent vasodilation was inversely correlated to the Ca++ level at baseline (r = −0.75, P < 0.05) and after PTH infusion (r = −0.68, P < 0.05). The vasodilatory function was not affected during PTH-infusion.

Effect of muscle strength and endurance development on blood flow

1961 ◽  
Vol 16 (5) ◽  
pp. 873-877 ◽  
Author(s):  
Ellen R. Vanderhoof ◽  
Charles J. Imig ◽  
H. M. Hines
Keyword(s):  
Blood Flow ◽  
Muscle Strength ◽  
Training Program ◽  
Strength Development ◽  
Flow Response ◽  
Hand Grip ◽  
Vascular Bed ◽  
Flow Through ◽  
Test Exercise ◽  
Strength Improvement

Studies were carried out to investigate the effect of hand grip strength and/or endurance improvement on blood flow through the muscles involved. One group of subjects trained for strength development and another for endurance development throughout a 29-week period. At regular intervals blood flow was measured under resting conditions and also following three different test exercise stresses designed to test the functional capacity of the vascular bed. Subjects who participated in the strength training program made significant gains in strength but not in endurance, while those subjects who trained for endurance improved in both strength and endurance. Resting blood flow was not changed significantly as a result of either training program. Significant changes in the blood flow response to the test exercise stresses were noted; these changes were associated with endurance rather than strength improvement. Submitted on April 3, 1961

scholarly journals Characterization of the microvascular cerebral blood flow response to obstructive apneic events during night sleep

2018 ◽  
Vol 5 (04) ◽  
pp. 1 ◽  
Author(s):  
Peyman Zirak ◽  
Clara Gregori-Pla ◽  
Igor Blanco ◽  
Ana Fortuna ◽  
Gianluca Cotta ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Night Sleep ◽  
Blood Flow Response ◽  
Flow Response

scholarly journals Activation of ATP-sensitive potassium channels contributes to reactive hyperemia in humans

1996 ◽  
Vol 271 (4) ◽  
pp. H1594-H1598 ◽  
Author(s):  
P. F. Banitt ◽  
P. Smits ◽  
S. B. Williams ◽  
P. Ganz ◽  
M. A. Creager
Keyword(s):  
Blood Flow ◽  
Katp Channel ◽  
Forearm Blood Flow ◽  
Reactive Hyperemia ◽  
Katp Channels ◽  
Venous Occlusion ◽  
Membrane Hyperpolarization ◽  
Flow Response ◽  
Hyperemic Flow ◽  
Basal Flow

Activation of ATP-sensitive potassium (KATP) channels present on vascular smooth muscle cells causes membrane hyperpolarization and vasodilation. The purpose of this study was to determine whether KATP channels contribute to reactive hyperemia in humans. Accordingly, we studied the effect of tolbutamide, a KATP channel inhibitor, on reactive hyperemic forearm blood flow. Forearm blood flow was measured by venous occlusion plethysmography. Forearm ischemia was produced by inflating a sphygmomanometric cuff on the arm to suprasystolic pressures for 5 min. After cuff release, forearm blood flow was measured during the reactive hyperemic phase for 5 min. Tolbutamide (1 mM blood concentration, n = 6) did not affect basal (2.4 +/- 0.2 to 2.2 +/- 0.1 ml.100 ml-1.min-1) or peak reactive hyperemic forearm blood flow (21.9 +/- 3.8 to 22.6 +/- 2.9 ml.100 ml-1.min-1, each P = NS), but it significantly attenuated total hyperemic volume (12.6 +/- 1.7 vs. 9.2 +/- 1.8 ml/100 ml, P < 0.02). Vehicle (n = 6) did not affect basal flow, peak reactive hyperemic flow, or total hyperemia. To determine whether adenosine or endothelium-derived nitric oxide contribute to reactive hyperemia via KATP channels, adenosine (1.5-500 micro grams/min, n = 6) and acetylcholine (30 micrograms/min, n = 6) were infused before and during tolbutamide coinfusion. Tolbutamide did not significantly alter the forearm blood flow response to either adenosine or acetylcholine. In conclusion, KATP channels contribute to vasodilation during reactive hyperemia in humans.

Effect of rhythmically inflating a pneumatic cuff at the ankle on blood flow in the foot

1959 ◽  
Vol 14 (3) ◽  
pp. 411-413 ◽  
Author(s):  
R. Andrew Loane
Keyword(s):  
Blood Flow ◽  
Heat Flow ◽  
Perfusion Pressure ◽  
Venous Pressure ◽  
Venous Occlusion ◽  
Quantitative Agreement ◽  
Venous Occlusion Plethysmography ◽  
Flow Through ◽  
And Calorimetry

Rhythmic inflation to 110 mm Hg of a pneumatic cuff around the ankle of a seated subject reduces the venous pressure in the foot and is found by three methods, venous occlusion plethysmography, heat flow and calorimetry, to increase the rate of blood flow through the foot. The increases measured by the three methods are not, however, in quantitative agreement and it is not possible to decide how large the increase may be. It is considered, however, that the increase in flow is probably of the same order as the increase in perfusion pressure and not greatly in excess of this increase. Submitted on August 5, 1958

Assessment of Peripheral Vascular Effects of Antimigraine Drugs in Humans

Cephalalgia ◽  
1995 ◽  
Vol 15 (4) ◽  
pp. 288-291 ◽  
Author(s):  
NM van Es ◽  
TA Bruning ◽  
J Camps ◽  
PC Chang ◽  
GJ Blauw ◽  
...  
Keyword(s):  
Blood Flow ◽  
Brachial Artery ◽  
Venous Occlusion ◽  
Finger Blood Flow ◽  
Peripheral Vascular ◽  
Vascular Effects ◽  
Antimigraine Drugs ◽  
Resistance Vessels ◽  
Vascular Beds ◽  
Therapeutic Doses

The vascular beds of the forearm and finger can be used to study the peripheral effects of antimigraine drugs under normal and pathologic circumstances. We have investigated the novel antimigraine drug sumatriptan, a selective agonist for 5HT1 receptors. Its antimigraine effect may be attributed, at least in part, to constriction of cranial arteriovenous anastomoses (AVAs). In assessing the peripheral vascular effects of sumatriptan we used a forearm and finger blood flow model. Forearm blood flow (FBF) is mainly determined by resistance vessels, whereas finger blood flow (FiBF) mainly involves skin vessels, which contain many AVAs. Changes in FBF and FiBF can be assessed using venous occlusion plethysmography. Changes in AVA flow are determined by measuring the patency of the vascular beds of the forearm and hand to well-defined radiolabeled microspheres, which are injected into the brachial artery. We report the effects of sumatriptan on FBF, FiBF and AVA flow when administered into the brachial artery of healthy volunteers, and discuss the peripheral vascular effects of therapeutic doses of sumatriptan when given subcutaneously in migraine patients during and between attacks.

Milking frequency alters the milk yield and mammary blood flow response to intra-mammary infusion of insulin-like growth factor-I in the goat

1992 ◽  
Vol 135 (2) ◽  
pp. 311-316 ◽  
Author(s):  
C. G. Prosser ◽  
S. R. Davis
Keyword(s):  
Blood Flow ◽  
Milk Yield ◽  
Flow Rate ◽  
Yield Response ◽  
Arterial Infusion ◽  
Blood Flow Response ◽  
Flow Response ◽  
Igf I ◽  
Flow Through ◽  
Milking Frequency

ABSTRACT The milk yield and mammary blood flow responses to close-arterial, intra-mammary infusion of IGF-I were investigated in five Saanen goats milked frequently or normally the day before. Animals were infused for 6 h with recombinant human IGF-I (1·3 nmol/min) and milked hourly following i.v. injection of oxytocin beginning 2 h before infusion and then every 2 h. On one occasion animals were milked five times (after i.v. injection of oxytocin) on the day before infusion and on the other they were milked twice, without oxytocin. The ratio of milk yield from the infused to that from non-infused gland increased by 17 ±4% (mean ± s.e.m.) in goats milked twice the day before infusion and by 6 ± 2% when the infusion was preceded by frequent milking. Maximal responses were obtained 4 h after the start of the infusion and differed significantly (P<0·05), according to pretreatment milking. Blood flow through the infused gland rose in parallel to the milk yield response. At 5 h, when maximal levels were achieved, blood flow was 182 ±23% of the pre-infusion flow rate following twice-daily milking and 139 ± 3% of the pre-infusion flow rate following more frequent milk removal. Thus, more frequent milk removal on the day before close-arterial infusion of IGF-I attenuated both the milk yield and mammary blood-flow response to the infusion of IGF-I. Journal of Endocrinology (1992) 135, 311–316

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