Impact of Cutaneous Blood Flow on NIR-DCS Measures of Skeletal Muscle Blood Flow Index

Author(s):  
Miles F. Bartlett ◽  
John D. Akins ◽  
Andrew Oneglia ◽  
R. Matthew Brothers ◽  
Dustin Wilkes ◽  
...  

Near-infrared diffuse correlation spectroscopy (NIR-DCS) is an optical technique for estimating relative changes in skeletal muscle perfusion during exercise, but may be affected by changes in cutaneous blood flow, as photons emitted by the laser must first pass through the skin. Accordingly, the purpose of this investigation was to examine how increased cutaneous blood flow affects NIR-DCS blood flow index (BFI) at rest and during exercise using a passive whole-body heating protocol that increases cutaneous, but not skeletal muscle, perfusion in the uncovered limb. BFI and cutaneous perfusion (laser Doppler flowmetry) were assessed in 15 healthy young subjects before (e.g., rest) and during 5-minutes of moderate-intensity hand-grip exercise in normothermic conditions and after cutaneous blood flow was elevated via whole-body heating. Hyperthermia significantly increased both cutaneous perfusion (~7.3-fold; p≤0.001) and NIR-DCS BFI (~4.5-fold; p≤0.001). Although relative BFI (i.e., fold-change above baseline) exhibited a typical exponential increase in muscle perfusion during normothermic exercise (2.81±0.95), there was almost no change in BFI during hyperthermic exercise (1.43±0.44). A subset of 8 subjects were subsequently treated with intradermal injection of botulinum toxin-A (Botox) to block heating-induced elevations in cutaneous blood flow, which 1) nearly abolished the hyperthermia-induced increase in BFI, and 2) restored BFI kinetics during hyperthermic exercise to values that were not different from normothermic exercise (p=0.091). Collectively, our results demonstrate that cutaneous blood flow can have a substantial, detrimental impact on NIR-DCS estimates of skeletal muscle perfusion and highlight the need for technical and/or pharmacological advancements to overcome this issue moving forward.

1963 ◽  
Vol 204 (2) ◽  
pp. 301-303 ◽  
Author(s):  
L. Takács ◽  
V. Vajda

The effects of intraperitoneal and intravenous administration of serotonin on cardiac output, blood pressure, and organ distribution of blood flow (Rb86) were studied in the rat. Fifteen to thirty minutes after intraperitoneal injection (10 mg/kg) cardiac output was unchanged, while blood pressure was significantly reduced. Increase in blood flow was noted in the myocardium, pulmonary parenchyma and "carcass" (skeletal muscle, bone, CNS), with decrease in the kidney and the skin. Splanchnic blood flow was unchanged. Conversely, intravenous infusion of serotonin produced an increase of cardiac output, blood pressure, and cutaneous blood flow.


Health ◽  
2014 ◽  
Vol 06 (10) ◽  
pp. 1049-1056 ◽  
Author(s):  
Seiko Yamaguchi ◽  
Yousuke Morita ◽  
Takehiko Yukishita ◽  
Keiko K. Lee ◽  
Takuji Yamaguchi ◽  
...  

2018 ◽  
Vol 125 (3) ◽  
pp. 697-705 ◽  
Author(s):  
Ting-Heng Chou ◽  
Jakob R. Allen ◽  
Dongwoo Hahn ◽  
Brian K. Leary ◽  
Edward F. Coyle

The decline in stroke volume (SV) during exercise in the heat has been attributed to either an increase in cutaneous blood flow (CBF) that reduces venous return or an increase in heart rate (HR) that reduces cardiac filling time. However, the evidence supporting each mechanism arises under experimental conditions with different skin temperatures (Tsk; e.g., ≥38°C vs. ≤36°C, respectively). We systematically studied cardiovascular responses to progressively increased Tsk (32°C–39°C) with narrowing of the core-to-skin gradient during moderate intensity exercise. Eight men cycled at 63 ± 1% peak oxygen consumption for 20–30 min. Tsk was manipulated by having subjects wear a water-perfused suit that covered most of the body and maintained Tsk that was significantly different between trials and averaged 32.4 ± 0.2, 35.5 ± 0.1, 37.5 ± 0.1, and 39.5 ± 0.1°C, respectively. The graded heating of Tsk ultimately produced a graded elevation of esophageal temperature (Tes) at the end of exercise. Incrementally increasing Tsk resulted in a graded increase in HR and a graded decrease in SV. CBF reached a similar average plateau value in all trials when Tes was above ~38°C, independent of Tsk. Tsk had no apparent effect on forearm venous volume (FVV). In conclusion, the CBF and FVV responses suggest no further pooling of blood in the skin when Tsk is increased from 32.4°C to 39.5°C. The decrease in SV during moderate intensity exercise when heating the skin to high levels appears related to an increase in HR and not an increase in CBF. NEW & NOTEWORTHY This study systematically investigated the effect of increasing skin temperature (Tsk) to high levels on cardiovascular responses during moderate intensity exercise. We conclude that the declines in stroke volume were related to the increases in heart rate but not the changes in cutaneous blood flow (CBF) and forearm venous volume (FVV) during moderate intensity exercise when Tsk increased from ~32°C to ~39°C. High Tsk (≥38°C) did not further elevate CBF and FVV compared with lower Tsk during moderate intensity exercise.


1997 ◽  
Vol 59 (2) ◽  
pp. 255-256
Author(s):  
Yuka NAKAMURA ◽  
Shinichi WATANABE ◽  
Hisashi TAKAHASHI ◽  
Atsuhiko HASEGAWA

1995 ◽  
Vol 268 (2) ◽  
pp. R492-R497 ◽  
Author(s):  
C. H. Lang ◽  
M. Ajmal ◽  
A. G. Baillie

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.


Aging Cell ◽  
2021 ◽  
Vol 20 (2) ◽  
Author(s):  
Carolyn Chee ◽  
Chris E. Shannon ◽  
Aisling Burns ◽  
Anna L. Selby ◽  
Daniel Wilkinson ◽  
...  

2011 ◽  
Vol 301 (2) ◽  
pp. E342-E350 ◽  
Author(s):  
A. J. Genders ◽  
E. A. Bradley ◽  
S. Rattigan ◽  
S. M. Richards

There is considerable support for the concept that insulin-mediated increases in microvascular blood flow to muscle impact significantly on muscle glucose uptake. Since the microvascular blood flow increases with insulin have been shown to be nitric oxide-dependent inhibition of cGMP-degrading phosphodiesterases (cGMP PDEs) is predicted to enhance insulin-mediated increases in microvascular perfusion and muscle glucose uptake. Therefore, we studied the effects of the pan-cGMP PDE inhibitor zaprinast on the metabolic and vascular actions of insulin in muscle. Hyperinsulinemic euglycemic clamps (3 mU·min−1·kg−1) were performed in anesthetized rats and changes in microvascular blood flow assessed from rates of 1-methylxanthine metabolism across the muscle bed by capillary xanthine oxidase in response to insulin and zaprinast. We also characterized cGMP PDE isoform expression in muscle by real-time PCR and immunostaining of frozen muscle sections. Zaprinast enhanced insulin-mediated microvascular perfusion by 29% and muscle glucose uptake by 89%, while whole body glucose infusion rate during insulin infusion was increased by 33% at 2 h. PDE2, -9, and -10 were the major isoforms expressed at the mRNA level in muscle, while PDE1B, -9A, -10A, and -11A proteins were expressed in blood vessels. Acute administration of the cGMP PDE inhibitor zaprinast enhances muscle microvascular blood flow and glucose uptake response to insulin. The expression of a number of cGMP PDE isoforms in skeletal muscle suggests that targeting specific cGMP PDE isoforms may provide a promising avenue for development of a novel class of therapeutics for enhancing muscle insulin sensitivity.


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