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The effect of nitric oxide synthase inhibition with and without inhibition of prostaglandins on blood flow in different human skeletal muscles

DOI:10.1007/s00421-017-3604-2
Authors:
Ilkka Heinonen at University of Turku
Ilkka Heinonen
Bengt Saltin
Bengt Saltin
Bengt Saltin
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Ylva Hellsten at University of Copenhagen
Ylva Hellsten
Kari Kalliokoski at University of Turku
Kari Kalliokoski
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Abstract and Figures

Purpose: Animal studies suggest that the inhibition of nitric oxide synthase (NOS) affects blood flow differently in different skeletal muscles according to their muscle fibre type composition (oxidative vs glycolytic). Quadriceps femoris (QF) muscle consists of four different muscle parts: vastus intermedius (VI), rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) of which VI is located deep within the muscle group and is generally regarded to consist mostly of oxidative muscle fibres. Methods: We studied the effect of NOS inhibition on blood flow in these four different muscles by positron emission tomography in eight young healthy men at rest and during one-leg dynamic exercise, with and without combined blockade with prostaglandins. Results: At rest blood flow in the VI (2.6 ± 1.1 ml/100 g/min) was significantly higher than in VL (1.9 ± 0.6 ml/100 g/min, p = 0.015) and RF (1.7 ± 0.6 ml/100 g/min, p = 0.0015), but comparable to VM (2.4 ± 1.1 ml/100 g/min). NOS inhibition alone or with prostaglandins reduced blood flow by almost 50% (p < 0.001), but decrements were similar in all four muscles (drug × muscle interaction, p = 0.43). During exercise blood flow was also the highest in VI (45.4 ± 5.5 ml/100 g/min) and higher compared to VL (35.0 ± 5.5 ml/100 g/min), RF (38.4 ± 7.4 ml/100 g/min), and VM (36.2 ± 6.8 ml/100 g/min). NOS inhibition alone did not reduce exercise hyperemia (p = 0.51), but combined NOS and prostaglandin inhibition reduced blood flow during exercise (p = 0.002), similarly in all muscles (drug × muscle interaction, p = 0.99). Conclusion: NOS inhibition, with or without prostaglandins inhibition, affects blood flow similarly in different human QF muscles both at rest and during low-to-moderate intensity exercise.
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Vol.:(0123456789)
1 3
Eur J Appl Physiol (2017) 117:1175–1180
DOI 10.1007/s00421-017-3604-2
ORIGINAL ARTICLE
The effect ofnitric oxide synthase inhibition withandwithout
inhibition ofprostaglandins onblood flow indifferent human
skeletal muscles
IlkkaHeinonen1,2,3 · BengtSaltin5· YlvaHellsten4· KariK.Kalliokoski1
Received: 22 November 2016 / Accepted: 22 March 2017 / Published online: 21 April 2017
© Springer-Verlag Berlin Heidelberg 2017
in VL (1.9 ± 0.6 ml/100 g/min, p = 0.015) and RF
(1.7±0.6ml/100g/min, p=0.0015), but comparable to
VM (2.4 ± 1.1 ml/100 g/min). NOS inhibition alone or
with prostaglandins reduced blood flow by almost 50%
(p<0.001), but decrements were similar in all four mus-
cles (drug×muscle interaction, p=0.43). During exercise
blood flow was also the highest in VI (45.4±5.5ml/100g/
min) and higher compared to VL (35.0 ± 5.5 ml/100 g/
min), RF (38.4 ± 7.4 ml/100 g/min), and VM
(36.2 ± 6.8 ml/100 g/min). NOS inhibition alone did not
reduce exercise hyperemia (p=0.51), but combined NOS
and prostaglandin inhibition reduced blood flow during
exercise (p=0.002), similarly in all muscles (drug×mus-
cle interaction, p=0.99).
Conclusion NOS inhibition, with or without prostaglan-
dins inhibition, affects blood flow similarly in different
human QF muscles both at rest and during low-to-moderate
intensity exercise.
Keywords Muscle fibres· Blood flow· Nitric oxide·
Prostanoids· Exercise· Humans
Abbreviations
NOS Nitric oxide synthase
VI Vastus intermedius
RF Rectus femoris
VM Vastus medialis
VL Vastus lateralis
Introduction
The continuous supply of oxygen via blood is of para-
mount importance for proper function of the muscle,
especially during exercise (Heinonen etal. 2014, 2015;
Abstract
Purpose Animal studies suggest that the inhibition of
nitric oxide synthase (NOS) affects blood flow differently
in different skeletal muscles according to their muscle fibre
type composition (oxidative vs glycolytic). Quadriceps
femoris (QF) muscle consists of four different muscle parts:
vastus intermedius (VI), rectus femoris (RF), vastus media-
lis (VM), and vastus lateralis (VL) of which VI is located
deep within the muscle group and is generally regarded to
consist mostly of oxidative muscle fibres.
Methods We studied the effect of NOS inhibition on
blood flow in these four different muscles by positron emis-
sion tomography in eight young healthy men at rest and
during one-leg dynamic exercise, with and without com-
bined blockade with prostaglandins.
Results At rest blood flow in the VI
(2.6 ± 1.1 ml/100 g/min) was significantly higher than
Communicated by: Keith Phillip George
Bengt Saltin: Deceased.
* Ilkka Heinonen
ilkka.heinonen@utu.fi
1 Turku PET Centre, University ofTurku, PO Box52,
20521Turku, Finland
2 Department ofClinical Physiology andNuclear Medicine,
University ofTurku, Turku, Finland
3 Division ofExperimental Cardiology, Thoraxcenter, Erasmus
MC, University Medical Center Rotterdam, Rotterdam,
TheNetherlands
4 Exercise andSport Sciences, Section ofHuman Physiology,
University ofCopenhagen, Copenhagen, Denmark
5 Copenhagen Muscle Research Center, University
ofCopenhagen, Copenhagen, Denmark
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
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Article
  • Jan 1973
Samples of skeletal muscle were taken from 50 sites in each of 6 previously normal male autopsy subjects aged between 17 and 30 years. The respective percentages of Type I and Type II fibres were calculated and showed that there was a wide variation in fibre type proportions between the 6 samples in almost all the muscles studied. Examination of the mean fibre type proportions of each muscle revealed that predominantly tonic muscles had a high percentage of Type I fibres and predominantly phasic muscles had a high percentage of Type II fibres. Most of the muscles studied were known to fulfil both tonic and phasic functions, however, and showed no striking preponderance of either fibre type.The spatial distribution of the fibre types was examined in order to determine whether this was random or not. The number of “enclosed” fibres observed in the actual samples was compared statistically with the number expected to occur in a hexagonal lattice model, assuming a random distribution. In the great majority of muscles, the distribution of the fibre types was in fact random, though isolated instances of grouping of fibres of uniform type were noted in some distal muscles and more regularly in extensor digitorum brevis.The methods used in the quantitative assessment of the proportions and spatial distribution of the respective fibre types in normal muscle have obvious applications in the study of neuromuscular disease.
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Peripheral Circulation
Article
  • Jan 2012
Blood flow (BF) increases with increasing exercise intensity in skeletal, respiratory, and cardiac muscle. In humans during maximal exercise intensities, 85% to 90% of total cardiac output is distributed to skeletal and cardiac muscle. During exercise BF increases modestly and heterogeneously to brain and decreases in gastrointestinal, reproductive, and renal tissues and shows little to no change in skin. If the duration of exercise is sufficient to increase body/core temperature, skin BF is also increased in humans. Because blood pressure changes little during exercise, changes in distribution of BF with incremental exercise result from changes in vascular conductance. These changes in distribution of BF throughout the body contribute to decreases in mixed venous oxygen content, serve to supply adequate oxygen to the active skeletal muscles, and support metabolism of other tissues while maintaining homeostasis. This review discusses the response of the peripheral circulation of humans to acute and chronic dynamic exercise and mechanisms responsible for these responses. This is accomplished in the context of leading the reader on a tour through the peripheral circulation during dynamic exercise. During this tour, we consider what is known about how each vascular bed controls BF during exercise and how these control mechanisms are modified by chronic physical activity/exercise training. The tour ends by comparing responses of the systemic circulation to those of the pulmonary circulation relative to the effects of exercise on the regional distribution of BF and mechanisms responsible for control of resistance/conductance in the systemic and pulmonary circulations. © 2012 American Physiological Society. Compr Physiol 2:321-447, 2012.
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