Endothelial Control of Shear Stress and Resistance in the Skeletal Muscle Microcirculation

1995 ◽  
pp. 236-260 ◽  
Author(s):  
Akos Koller ◽  
Gabor Kaley
Keyword(s):  
Skeletal Muscle ◽  
Shear Stress ◽  
Skeletal Muscle Microcirculation ◽  
Endothelial Control

Endothelial regulation of wall shear stress and blood flow in skeletal muscle microcirculation

1991 ◽  
Vol 260 (3) ◽  
pp. H862-H868 ◽  
Author(s):  
A. Koller ◽  
G. Kaley
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Flow Velocity ◽  
Cremaster Muscle ◽  
Skeletal Muscle Microcirculation ◽  
Wall Shear ◽  
Arteriolar Diameter ◽  
Dependent Mechanism

In the presence of intact endothelium, in control conditions, calculated wall shear rate (WSR) (means +/- SE: 2,658 +/- 123 s-1; n = 21) was independent of arteriolar diameter (16.2-27.2 microns; correlation coefficient: r = 0.12, P greater than 0.05) in cremaster muscle of pentobarbital-anesthetized rats. An increase in blood flow velocity (due to parallel arteriolar occlusion) elicited a significant increase in WSR (to 4,981 +/- 253 s-1) followed by a delayed (6-15 s) increase in diameter (from: 22.5 +/- 0.6 to 29.5 +/- 0.8 microns), which consequently resulted in a significant decrease in WSR (to 3,879 +/- 203 s-1). As a result of the increased flow velocity and dilation, calculated arteriolar blood flow increased by 230%. After impairment of the endothelium of arterioles by a light-dye technique, basal WSR became significantly higher (3,604 +/- 341 s-1), and despite a greater increase in WSR (10,360 +/- 1,471 s-1) the dilation was absent. Now an inverse linear correlation was found between arteriolar diameter and WSR both before (r = 0.58, P less than 0.05) and during increased flow velocity conditions (r = 0.85, P less than 0.05). Also, arteriolar blood flow that was already less after impairment of endothelium increased by only 66% during the period of increased flow velocity due to the absence of dilation. Results suggest that an increase in wall shear stress is the stimulus for the endothelium-dependent mechanism that elicits "flow dependent" arteriolar dilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulsatile Pressure and Flow in the Skeletal Muscle Microcirculation

1990 ◽  
Vol 112 (4) ◽  
pp. 437-443 ◽  
Author(s):  
Shou-Yan Lee ◽  
G. W. Schmid-Scho¨nbein
Keyword(s):  
Skeletal Muscle ◽  
Arterial Pressure ◽  
Time Course ◽  
Venous Pressure ◽  
Time Dependent ◽  
Physiological Importance ◽  
Pulsatile Pressure ◽  
Theoretical Predictions ◽  
Skeletal Muscle Microcirculation

Although blood flow in the microcirculation of the rat skeletal muscle has negligible inertia forces with very low Reynolds number and Womersley parameter, time-dependent pressure and flow variations can be observed. Such phenomena include, for example, arterial flow overshoot following a step arterial pressure, a gradual arterial pressure reduction for a step flow, or hysteresis between pressure and flow when a pulsatile pressure is applied. Arterial and venous flows do not follow the same time course during such transients. A theoretical analysis is presented for these phenomena using a microvessel with distensible viscoelastic walls and purely viscous flow subject to time variant arterial pressures. The results indicate that the vessel distensibility plays an important role in such time-dependent microvascular flow and the effects are of central physiological importance during normal muscle perfusion. In-vivo whole organ pressure-flow data in the dilated rat gracilis muscle agree in the time course with the theoretical predictions. Hemodynamic impedances of the skeletal muscle microcirculation are investigated for small arterial and venous pressure amplitudes superimposed on an initial steady flow and pressure drop along the vessel.

scholarly journals Photoacoustic Imaging for the Detection of Hypoxia in the Rat Femoral Artery and Skeletal Muscle Microcirculation

Shock ◽  
2016 ◽  
Vol 46 (5) ◽  
pp. 527-530 ◽  
Author(s):  
Lane M. Smith ◽  
Jasmina Varagic ◽  
Liliya M. Yamaleyeva
Keyword(s):  
Skeletal Muscle ◽  
Femoral Artery ◽  
Photoacoustic Imaging ◽  
Skeletal Muscle Microcirculation

Coordinated diameter oscillations at arteriolar bifurcations in skeletal muscle

1987 ◽  
Vol 253 (3) ◽  
pp. H568-H573 ◽  
Author(s):  
J. U. Meyer ◽  
L. Lindbom ◽  
M. Intaglietta
Keyword(s):  
Skeletal Muscle ◽  
Fundamental Frequency ◽  
Narrow Band ◽  
Photometric System ◽  
Band Frequency ◽  
Skeletal Muscle Microcirculation

The spontaneous rhythmical luminal changes (vasomotion) at bifurcations in the microvasculature of the rabbit tenuissimus muscle were investigated by means of a microscope video photometric system. Video scenes, containing two terminal arterioles originating from one transverse arteriole, showed that adjacent terminal arterioles constricted synchronously in 26 out of 31 contraction cycles. The onset of 60 constrictions in the parent transverse vessels was synchronized with the activity in terminal arterioles in 75% of the cycles and delayed in 25%. Vasomotion in the parent transverse vessels was notably smaller than in the terminal vessels. All the terminal arterioles in the different animals oscillated at the fundamental frequency of 18.9 +/- 3.5 cycles/min. We conclude that in the skeletal muscle microcirculation 1) coordinated spontaneous diameter oscillations occur in arterioles that are in proximity, 2) diameter changes are most pronounced in the terminal arterioles, and 3) coordinated vasomotion in this tissue exhibits a characteristic narrow band frequency. The presence of a microvascular pacemaker is hypothesized.

scholarly journals Aerobic Exercise Attenuates Pressure Overload-Induced Cardiac Dysfunction through Promoting Skeletal Muscle Microcirculation and Increasing Muscle Mass

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ling-Yan Yuan ◽  
Pei-Zhao Du ◽  
Min-Min Wei ◽  
Qi Zhang ◽  
Le Lu ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cardiac Function ◽  
Aerobic Exercise ◽  
Muscle Mass ◽  
Cardiac Dysfunction ◽  
Pressure Overload ◽  
Transverse Aortic Constriction ◽  
Aortic Constriction ◽  
Protein Levels ◽  
Skeletal Muscle Microcirculation

Background. Aerobic exercise has been proven to have a positive effect on cardiac function after hypertension; however, the mechanism is not entirely clarified. Skeletal muscle mass and microcirculation are closely associated with blood pressure and cardiac function. Objective. This study was designed to investigate the effects of aerobic exercise on the skeletal muscle capillary and muscle mass, to explore the possible mechanisms involved in exercise-induced mitigation of cardiac dysfunction in pressure overload mice. Methods. In this study, 60 BALB/C mice aged 8 weeks were randomly divided into 3 groups: control (CON), TAC, and TAC plus exercise (TAE) group and utilized transverse aortic constriction (TAC) to establish hypertensive model; meanwhile, treadmill training is used for aerobic exercise. After 5 days of recovery, mice in the TAE group were subjected to 10-week aerobic exercise. Carotid pressure and cardiac function were examined before mice were executed by Millar catheter and ultrasound, respectively. Muscle mass of gastrocnemius was weighed; cross-sectional area and the number of capillaries of gastrocnemius were detected by HE and immunohistochemistry, respectively. The mRNA and protein levels of VEGF in skeletal muscle were determined by RT-PCR and western blot, respectively. Results. We found that ① 10-week aerobic exercise counteracted hypertension and attenuated cardiac dysfunction in TAC-induced hypertensive mice; ② TAC decreased muscle mass of gastrocnemius and resulted in muscle atrophy, while 10-week aerobic exercise could reserve transverse aortic constriction-induced the decline of muscle mass and muscle atrophy; and ③ TAC reduced the number of capillaries and the protein level of VEGF in gastrocnemius, whereas 10-week aerobic exercise augmented the number of capillaries, the mRNA and protein levels of VEGF in mice were subjected to TAC surgery. Conclusions. This study indicates that 10-week aerobic exercise might fulfill its blood pressure-lowering effect via improving skeletal muscle microcirculation and increasing muscle mass.

scholarly journals Impaired skeletal muscle microcirculation in systemic sclerosis

2012 ◽  
Vol 14 (5) ◽  
pp. R209 ◽  
Author(s):  
Sasan Partovi ◽  
Anja-Carina Schulte ◽  
Markus Aschwanden ◽  
Daniel Staub ◽  
Daniela Benz ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Systemic Sclerosis ◽  
Skeletal Muscle Microcirculation

Endothelium regulates skeletal muscle microcirculation by a blood flow velocity-sensing mechanism

1990 ◽  
Vol 258 (3) ◽  
pp. H916-H920 ◽  
Author(s):  
A. Koller ◽  
G. Kaley
Keyword(s):  
Skeletal Muscle ◽  
Endothelial Cells ◽  
Blood Flow ◽  
Flow Velocity ◽  
Cremaster Muscle ◽  
Positive Linear Correlation ◽  
Skeletal Muscle Microcirculation ◽  
Per Se ◽  
Dependent Flow

In rat cremaster muscle, utilizing parallel arteriolar occlusion, we found that an increase in red blood cell (RBC) velocity (3.5-26.5 mm/s) per se induced an increase in diameter (1.5-9.4 microns) of arterioles (mean control diam 21.5 +/- 0.6 microns; n = 25). The dilation of arterioles appeared only when RBC velocity increased and started always with a delay (mean 8.4 +/- 0.5 s) after the increase in flow velocity. A positive linear correlation was found between peak changes in RBC velocity and diameter (r = 0.87, P less than 0.05). The velocity sensor as well as the mechanism(s) that mediates this response is likely to be located in endothelial cells, because the dilation to increased RBC velocity was completely eliminated after impairment of arteriolar endothelium with light-dye (L-D) treatment. The in vivo demonstration of this phenomenon in arterioles suggests the existence of a new endothelium-dependent, flow velocity-sensitive mechanism for the regulation of blood flow in the microcirculation.

Dynamic Contrast-Enhanced Ultrasound for Assessment of Skeletal Muscle Microcirculation in Peripheral Arterial Disease

2011 ◽  
Vol 46 (8) ◽  
pp. 504-508 ◽  
Author(s):  
Erick Amarteifio ◽  
Marc-André Weber ◽  
Stephanie Wormsbecher ◽  
Serdar Demirel ◽  
Holger Krakowski-Roosen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Peripheral Arterial Disease ◽  
Arterial Disease ◽  
Contrast Enhanced Ultrasound ◽  
Dynamic Contrast Enhanced ◽  
Contrast Enhanced ◽  
Skeletal Muscle Microcirculation ◽  
Peripheral Arterial
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