scholarly journals Local, but not indirect whole body heating, increases human skeletal muscle blood flow

2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
Illka Heinonen ◽  
R. Matthew Brothers ◽  
Jukka Kemppainen ◽  
Juhani Knuuti ◽  
Kari K. Kalliokoski ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Human Skeletal Muscle ◽  
Muscle Blood Flow ◽  
Whole Body ◽  
Skeletal Muscle Blood Flow

scholarly journals Erythrocytes and the regulation of human skeletal muscle blood flow and oxygen delivery: role of erythrocyte count and oxygenation state of haemoglobin

2006 ◽  
Vol 572 (1) ◽  
pp. 295-305 ◽  
Author(s):  
José González-Alonso ◽  
Stefan P. Mortensen ◽  
Ellen A. Dawson ◽  
Niels H. Secher ◽  
Rasmus Damsgaard
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Oxygen Delivery ◽  
Human Skeletal Muscle ◽  
Muscle Blood Flow ◽  
Erythrocyte Count ◽  
Skeletal Muscle Blood Flow

scholarly journals Local heating, but not indirect whole body heating, increases human skeletal muscle blood flow

2011 ◽  
Vol 111 (3) ◽  
pp. 818-824 ◽  
Author(s):  
Ilkka Heinonen ◽  
R. Matthew Brothers ◽  
Jukka Kemppainen ◽  
Juhani Knuuti ◽  
Kari K. Kalliokoski ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Heat Stress ◽  
Local Heating ◽  
Muscle Blood Flow ◽  
Whole Body ◽  
Skeletal Muscle Blood Flow ◽  
Whole Body Heat Stress ◽  
Body Heat ◽  
Indirect Heating

For decades it was believed that direct and indirect heating (the latter of which elevates blood and core temperatures without directly heating the area being evaluated) increases skin but not skeletal muscle blood flow. Recent results, however, suggest that passive heating of the leg may increase muscle blood flow. Using the technique of positron-emission tomography, the present study tested the hypothesis that both direct and indirect heating increases muscle blood flow. Calf muscle and skin blood flows were evaluated from eight subjects during normothermic baseline, during local heating of the right calf [only the right calf was exposed to the heating source (water-perfused suit)], and during indirect whole body heat stress in which the left calf was not exposed to the heating source. Local heating increased intramuscular temperature of the right calf from 33.4 ± 1.0°C to 37.4 ± 0.8°C, without changing intestinal temperature. This stimulus increased muscle blood flow from 1.4 ± 0.5 to 2.3 ± 1.2 ml·100 g−1·min−1 ( P < 0.05), whereas skin blood flow under the heating source increased from 0.7 ± 0.3 to 5.5 ± 1.5 ml·100 g−1·min−1 ( P < 0.01). While whole body heat stress increased intestinal temperature by ∼1°C, muscle blood flow in the calf that was not directly exposed to the water-perfused suit (i.e., indirect heating) did not increase during the whole body heat stress (normothermia: 1.6 ± 0.5 ml·100 g−1·min−1; heat stress: 1.7 ± 0.3 ml·100 g−1·min−1; P = 0.87). Whole body heating, however, reflexively increased calf skin blood flow (to 4.0 ± 1.5 ml·100 g−1·min−1) in the area not exposed to the water-perfused suit. These data show that local, but not indirect, heating increases calf skeletal muscle blood flow in humans. These results have important implications toward the reconsideration of previously accepted blood flow distribution during whole body heat stress.

scholarly journals Combined inhibition of nitric oxide and prostaglandins reduces human skeletal muscle blood flow during exercise

2002 ◽  
Vol 543 (2) ◽  
pp. 691-698 ◽  
Author(s):  
Robert Boushel ◽  
Henning Langberg ◽  
Carsten Gemmer ◽  
Jens Olesen ◽  
Regina Crameri ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Human Skeletal Muscle ◽  
Muscle Blood Flow ◽  
Skeletal Muscle Blood Flow

scholarly journals Erythrocyte and the Regulation of Human Skeletal Muscle Blood Flow and Oxygen Delivery

2002 ◽  
Vol 91 (11) ◽  
pp. 1046-1055 ◽  
Author(s):  
José González-Alonso ◽  
David B. Olsen ◽  
Bengt Saltin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Oxygen Delivery ◽  
Human Skeletal Muscle ◽  
Muscle Blood Flow ◽  
Skeletal Muscle Blood Flow

scholarly journals Erythrocyte-dependent regulation of human skeletal muscle blood flow: role of varied oxyhemoglobin and exercise on nitrite, S-nitrosohemoglobin, and ATP

2010 ◽  
Vol 299 (6) ◽  
pp. H1936-H1946 ◽  
Author(s):  
Stéphane P. Dufour ◽  
Rakesh P. Patel ◽  
Angela Brandon ◽  
Xinjun Teng ◽  
James Pearson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Human Skeletal Muscle ◽  
Muscle Blood Flow ◽  
Knee Extensor ◽  
Tissue Perfusion ◽  
Hypoxic Stress ◽  
Skeletal Muscle Blood Flow ◽  
Plasma Nitrite

The erythrocyte is proposed to play a key role in the control of local tissue perfusion via three O2-dependent signaling mechanisms: 1) reduction of circulating nitrite to vasoactive NO, 2) S-nitrosohemoglobin (SNO-Hb)-dependent vasodilatation, and 3) release of the vasodilator and sympatholytic ATP; however, their relative roles in vivo remain unclear. Here we evaluated each mechanism to gain insight into their roles in the regulation of human skeletal muscle blood flow during hypoxia and hyperoxia at rest and during exercise. Arterial and femoral venous hemoglobin O2 saturation (O2Hb), plasma and erythrocyte NO and ATP metabolites, and leg and systemic hemodynamics were measured in 10 healthy males exposed to graded hypoxia, normoxia, and graded hyperoxia both at rest and during submaximal one-legged knee-extensor exercise. At rest, leg blood flow and NO and ATP metabolites in plasma and erythrocytes remained unchanged despite large alterations in O2Hb. During exercise, however, leg and systemic perfusion and vascular conductance increased in direct proportion to decreases in arterial and venous O2Hb ( r2 = 0.86–0.98; P = 0.01), decreases in venous plasma nitrite ( r2 = 0.93; P < 0.01), increases in venous erythrocyte nitroso species ( r2 = 0.74; P < 0.05), and to a lesser extent increases in erythrocyte SNO ( r2 = 0.59; P = 0.07). No relationship was observed with plasma ATP ( r2 = 0.01; P = 0.99) or its degradation compounds. These in vivo data indicate that, during low-intensity exercise and hypoxic stress, but not hypoxic stress alone, plasma nitrite consumption and formation of erythrocyte nitroso species are associated with limb vasodilatation and increased blood flow in the human skeletal muscle vasculature.

scholarly journals Sodium nitroprusside increases human skeletal muscle blood flow, but does not change flow distribution or glucose uptake

1999 ◽  
Vol 521 (3) ◽  
pp. 729-737 ◽  
Author(s):  
Olli-Pekka Pitkänen ◽  
Hanna Laine ◽  
Jukka Kemppainen ◽  
Esa Eronen ◽  
Anu Alanen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Sodium Nitroprusside ◽  
Glucose Uptake ◽  
Human Skeletal Muscle ◽  
Muscle Blood Flow ◽  
Flow Distribution ◽  
Skeletal Muscle Blood Flow

Systemic Nitric Oxide Synthase Inhibition Increases Insulin Sensitivity in Man

1998 ◽  
Vol 94 (2) ◽  
pp. 175-180 ◽  
Author(s):  
R. Butler ◽  
A.D. Morris ◽  
A. D. Struthers
Keyword(s):  
Nitric Oxide ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Insulin Sensitivity ◽  
Nitric Oxide Synthase ◽  
Glucose Uptake ◽  
Muscle Blood Flow ◽  
Whole Body ◽  
Skeletal Muscle Blood Flow ◽  
Oxide Synthase

1. Recent evidence shows that skeletal muscle blood flow is an important determinant of insulin sensitivity and that insulin-mediated vasodilatation is nitric oxide dependent. These results have given rise to the hypothesis that endothelial nitric oxide inhibition may decrease insulin sensitivity in humans. 2. We examined this hypothesis directly by evaluating the effects of systemic nitric oxide synthase inhibition with NG-monomethyl l-arginine (3 mg h−1 kg−1) on whole-body glucose uptake (euglycaemic hyperinsulinaemic clamp) and calf blood flow (bilateral calf venous occlusion plethysmography) in 16 healthy male subjects in a randomized, double-blind, placebo-controlled, crossover study. 3. NG-Monomethyl l-arginine infusion was associated with a pressor effect (119/61 ± 2/2 compared with 114/58 ± 2/2 mmHg for placebo; P < 0.001), and a negative chronotropic response (57 ± 2 compared with 62 ± 2 beats/min for placebo; P < 0.001). The glucose infusion rate was significantly increased after infusion of NG-monomethyl l-arginine (8.9 ± 0.9 compared with 7.9 ± 0.8 mg min−1 kg−1 for placebo; P = 0.002). Whole-body glucose uptake increased during the clamp, with values of 9.4 ± 0.7 and 10.9 ± 0.8 mg min−1 kg−1 for placebo and NG-monomethyl l-arginine respectively (P = 0.036; 95% confidence interval 0.2,2.8). NG-Monomethyl l-arginine was associated with increased calf blood flow by comparison with placebo (P < 0.05, area under curve). 4. These data show for the first time that systemic inhibition of nitric oxide synthesis increases rather than decreases whole-body glucose uptake. We suggest that the higher skeletal muscle blood flow seen after NG-monomethyl l-arginine may explain the observed increase in whole-body glucose uptake.

scholarly journals Folic acid ingestion improves skeletal muscle blood flow during graded handgrip and plantar flexion exercise in aged humans

2017 ◽  
Vol 313 (3) ◽  
pp. H658-H666 ◽  
Author(s):  
Steven A. Romero ◽  
Daniel Gagnon ◽  
Amy N. Adams ◽  
Gilbert Moralez ◽  
Ken Kouda ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Folic Acid ◽  
Muscle Blood Flow ◽  
Plantar Flexion ◽  
Serum Folate ◽  
Whole Body ◽  
Vascular Conductance ◽  
Skeletal Muscle Blood Flow ◽  
Plantar Flexion Exercise

Skeletal muscle blood flow is attenuated in aged humans performing dynamic exercise, which is due, in part, to impaired local vasodilatory mechanisms. Recent evidence suggests that folic acid improves cutaneous vasodilation during localized and whole body heating through nitric oxide-dependent mechanisms. However, it is unclear whether folic acid improves vasodilation in other vascular beds during conditions of increased metabolism (i.e., exercise). The purpose of this study was to test the hypothesis that folic acid ingestion improves skeletal muscle blood flow in aged adults performing graded handgrip and plantar flexion exercise via increased vascular conductance. Nine healthy, aged adults (two men and seven women; age: 68 ± 5 yr) performed graded handgrip and plantar flexion exercise before (control), 2 h after (acute, 5 mg), and after 6 wk (chronic, 5 mg/day) folic acid ingestion. Forearm (brachial artery) and leg (superficial femoral artery) blood velocity and diameter were measured via Duplex ultrasonography and used to calculate blood flow. Acute and chronic folic acid ingestion increased serum folate (both P < 0.05 vs. control). During handgrip exercise, acute and chronic folic acid ingestion increased forearm blood flow (both conditions P < 0.05 vs. control) and vascular conductance (both P < 0.05 vs. control). During plantar flexion exercise, acute and chronic folic acid ingestion increased leg blood flow (both P < 0.05 vs. control), but only acute folic acid ingestion increased vascular conductance ( P < 0.05 vs. control). Taken together, folic acid ingestion increases blood flow to active skeletal muscle primarily via improved local vasodilation in aged adults. NEW & NOTEWORTHY Our findings demonstrate that folic acid ingestion improves blood flow via enhanced vascular conductance in the exercising skeletal muscle of aged humans. These findings provide evidence for the therapeutic use of folic acid to improve skeletal muscle blood flow, and perhaps exercise and functional capacity, in human primary aging. Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/folic-acid-and-exercise-hyperemia-in-aging/ .

Neural control of glucose uptake by skeletal muscle after central administration of NMDA

1995 ◽  
Vol 268 (2) ◽  
pp. R492-R497 ◽  
Author(s):  
C. H. Lang ◽  
M. Ajmal ◽  
A. G. Baillie
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Glucose Uptake ◽  
Neural Control ◽  
Plasma Insulin ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Whole Body ◽  
Glucose Disposal ◽  
Central Administration

Intracerebroventricular injection of N-methyl-D-aspartate (NMDA) produces hyperglycemia and increases whole body glucose uptake. The purpose of the present study was to determine in rats which tissues are responsible for the elevated rate of glucose disposal. NMDA was injected intracerebroventricularly, and the glucose metabolic rate (Rg) was determined for individual tissues 20-60 min later using 2-deoxy-D-[U-14C]glucose. NMDA decreased Rg in skin, ileum, lung, and liver (30-35%) compared with time-matched control animals. In contrast, Rg in skeletal muscle and heart was increased 150-160%. This increased Rg was not due to an elevation in plasma insulin concentrations. In subsequent studies, the sciatic nerve in one leg was cut 4 h before injection of NMDA. NMDA increased Rg in the gastrocnemius (149%) and soleus (220%) in the innervated leg. However, Rg was not increased after NMDA in contralateral muscles from the denervated limb. Data from a third series of experiments indicated that the NMDA-induced increase in Rg by innervated muscle and its abolition in the denervated muscle were not due to changes in muscle blood flow. The results of the present study indicate that 1) central administration of NMDA increases whole body glucose uptake by preferentially stimulating glucose uptake by skeletal muscle, and 2) the enhanced glucose uptake by muscle is neurally mediated and independent of changes in either the plasma insulin concentration or regional blood flow.

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