MRI analyses indicate non-uniform human muscle tissue deformations and confirm theoretically anticipated sarcomere length heterogeneity, in vivo

2014 ◽  
Author(s):  
Uluc Pamuk ◽  
Agah Karakuzu ◽  
Pinar Akyazi ◽  
Burak Acar ◽  
Cengizhan Ozturk ◽  
...  
Keyword(s):  
Muscle Tissue ◽  
Sarcomere Length ◽  
Human Muscle ◽  
Tissue Deformations

In vivo observation of quadrupolar splitting in 39 K magnetic resonance spectroscopy of human muscle tissue

2016 ◽  
Vol 29 (4) ◽  
pp. 451-457 ◽  
Author(s):  
M. B. Rösler ◽  
A. M. Nagel ◽  
R. Umathum ◽  
P. Bachert ◽  
N. Benkhedah
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Muscle Tissue ◽  
Human Muscle ◽  
Resonance Spectroscopy ◽  
Quadrupolar Splitting

scholarly journals Microendoscopy reveals positive correlation in multiscale length changes and variable sarcomere lengths across different regions of human muscle

2018 ◽  
Vol 125 (6) ◽  
pp. 1812-1820 ◽  
Author(s):  
Glen A. Lichtwark ◽  
Dominic J. Farris ◽  
Xuefeng Chen ◽  
Paul W. Hodges ◽  
Scott L. Delp
Keyword(s):  
Tibialis Anterior ◽  
Sarcomere Length ◽  
Length Change ◽  
Human Muscle ◽  
Fascicle Length ◽  
Needle Probe ◽  
Distal Location ◽  
Length Changes ◽  
Sarcomere Number

Sarcomere length is a key physiological parameter that affects muscle force output; however, our understanding of the scaling of human muscle from sarcomere to whole muscle is based primarily on cadaveric data. The aims of this study were to explore the in vivo relationship between passive fascicle length and passive sarcomere length at different muscle-tendon unit lengths and determine whether sarcomere and fascicle length relationships are the same in different regions of muscle. A microendoscopy needle probe capable of in vivo sarcomere imaging was inserted into a proximal location of the human tibialis anterior muscle at three different ankle positions [5° dorsiflexion, 5° plantar flexion (PF), and 15° PF] and one distal location at a constant ankle position (5° PF distal). Ultrasound imaging of tibialis anterior fascicles, centered on the location of the needle probe, was performed for each condition to estimate fascicle length. Sarcomere length and fascicle length increased with increasing muscle-tendon unit length, although the correlation between sarcomere length change and muscle fascicle length change was only moderate ( r2 = 0.45). Passive sarcomere length was longer at the distal imaging site than the proximal site ( P = 0.01). When sarcomere number was estimated from sarcomere length and fascicle length, there were fewer sarcomeres in the fibers of distal location than the proximal location ( P = 0.01). These data demonstrate that fascicle length changes are representative of sarcomere length changes, although significant variability in sarcomere length exists within a muscle and sarcomere number per fiber is region-dependent. NEW & NOTEWORTHY Sarcomere and fascicle lengths were measured in vivo from human muscle to examine the relationship between the different scales of organization. Changes in fascicle length were moderately related to sarcomere length changes; however, sarcomere length and number per fiber varied from proximal to distal regions of the muscle. Differences in average sarcomere operating lengths across the muscle suggest potentially different stresses or strains experienced within different regions of muscle.

scholarly journals In vivo human gracilis whole muscle passive stress-sarcomere strain relationship

2021 ◽  
Author(s):  
Lomas S. Persad ◽  
Benjamin I. Binder-Markey ◽  
Alexander Y. Shin ◽  
Kenton R. Kaufman ◽  
Richard L. Lieber
Keyword(s):  
Mechanical Properties ◽  
Sarcomere Length ◽  
Mammalian Species ◽  
Muscle Length ◽  
Human Muscle ◽  
Gracilis Muscle ◽  
Rabbit Muscle ◽  
Cross Sectional ◽  
Whole Muscle

We measured the passive mechanical properties of intact, living human gracilis muscles (n=11 individuals, 1 female, age: 33±12years, mass: 89±23kg, height: 177±8cm). Measurements were performed in patients undergoing surgery for free functioning myocutaneous tissue transfer of the gracilis muscle to restore elbow flexion after brachial plexus injury. Whole muscle force of the gracilis tendon was measured in four joint configurations (JC1-JC4) with a buckle force transducer placed at the distal tendon. Sarcomere length was also measured by biopsy from the proximal gracilis muscle. After the muscle was removed a three-dimensional volumetric reconstruction of the muscle was created via photogrammetry. Muscle length from JC1 to JC4 increased by 3.3±1.0 cm, 7.7±1.2 cm, 10.5±1.3 cm and 13.4±1.2 cm respectively, corresponding to 15%, 34%, 46% and 59% muscle fiber strain respectively. Muscle volume and an average optimal fiber length of 23.1±0.7 cm yielded an average muscle physiological cross-sectional area of 6.8±0.7 cm2 which is approximately three times that measured previously from cadaveric specimens. Absolute passive tension increased from 0.90±0.21 N in JC1 to 16.50±2.64 N in JC4. As expected, sarcomere length also increased from 3.24±0.08 µm at JC1 to 3.63±0.07 µm at JC4, which are on the descending limb of the human sarcomere length-tension curve. Peak passive muscle stress was 27.8±5.5 kPa in JC4 and muscle modulus ranged from 44.8 MPa in JC1 to 125.7 MPa in JC4. Compared to other mammalian species, human muscle passive mechanical properties are more similar to rodent muscle than rabbit muscle. These data provide direct measurements of whole human muscle passive mechanical properties that can be used in modeling studies and for understanding comparative passive mechanical properties among mammalian muscles.

Psoas Muscle Architectural Design, In Vivo Sarcomere Length Range, and Passive Tensile Properties Support Its Role as a Lumbar Spine Stabilizer

Spine ◽  
2011 ◽  
Vol 36 (26) ◽  
pp. E1666-E1674 ◽  
Author(s):  
Gilad J. Regev ◽  
Choll W. Kim ◽  
Akihito Tomiya ◽  
Yu Po Lee ◽  
Hossein Ghofrani ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Tensile Properties ◽  
Architectural Design ◽  
Sarcomere Length ◽  
Psoas Muscle ◽  
Length Range

In vivo microvascular structural and functional consequences of muscle length changes

1997 ◽  
Vol 272 (5) ◽  
pp. H2107-H2114 ◽  
Author(s):  
D. C. Poole ◽  
T. I. Musch ◽  
C. A. Kindig
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Oxygen Delivery ◽  
Sarcomere Length ◽  
Flow Dynamics ◽  
Capillary Diameter ◽  
Luminal Diameter ◽  
Length Changes

As muscles are stretched, blood flow and oxygen delivery are compromised, and consequently muscle function is impaired. We tested the hypothesis that the structural microvascular sequellae associated with muscle extension in vivo would impair capillary red blood cell hemodynamics. We developed an intravital spinotrapezius preparation that facilitated direct on-line measurement and alteration of sarcomere length simultaneously with determination of capillary geometry and red blood cell flow dynamics. The range of spinotrapezius sarcomere lengths achievable in vivo was 2.17 +/- 0.05 to 3.13 +/- 0.11 microns. Capillary tortuosity decreased systematically with increases of sarcomere length up to 2.6 microns, at which point most capillaries appeared to be highly oriented along the fiber longitudinal axis. Further increases in sarcomere length above this value reduced mean capillary diameter from 5.61 +/- 0.03 microns at 2.4-2.6 microns sarcomere length to 4.12 +/- 0.05 microns at 3.2-3.4 microns sarcomere length. Over the range of physiological sarcomere lengths, bulk blood flow (radioactive microspheres) decreased approximately 40% from 24.3 +/- 7.5 to 14.5 +/- 4.6 ml.100 g-1.min-1. The proportion of continuously perfused capillaries, i.e., those with continuous flow throughout the 60-s observation period, decreased from 95.9 +/- 0.6% at the shortest sarcomere lengths to 56.5 +/- 0.7% at the longest sarcomere lengths and was correlated significantly with the reduced capillary diameter (r = 0.711, P < 0.01; n = 18). We conclude that alterations in capillary geometry and luminal diameter consequent to increased muscle sarcomere length are associated with a reduction in mean capillary red blood cell velocity and a greater proportion of capillaries in which red blood cell flow is stopped or intermittent. Thus not only does muscle stretching reduce bulk blood (and oxygen) delivery, it also alters capillary red blood cell flow dynamics, which may further impair blood-tissue oxygen exchange.

Abstract 5402: Two Photon Microscopy Measurements Of Sub-epicardial Sarcomere Length In Perfused Rat Hearts

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Patrizia Camelliti ◽  
Gil Bub ◽  
Daniel J Stuckey ◽  
Christian Bollensdorff ◽  
Damian J Tyler ◽  
...  
Keyword(s):  
Sarcomere Length ◽  
Left Ventricular ◽  
Model Systems ◽  
Future Research ◽  
Fundamental Parameter ◽  
Rat Hearts ◽  
Perfused Hearts ◽  
Over Time

Sarcomere length (SL) is a fundamental parameter underlying the Frank Starling relation in the heart, as it offers an absolute representation of myocardial stretch. Previous studies addressed the Frank Starling relation by measuring SL in isolated myocytes or muscle strips. Here, we report first data obtained using a novel technique to measure sub-epicardial SL in perfused hearts. Rat hearts were Langendorff perfused (normal Tyrode solution) at a constant pressure of 90mmHg, labeled with the fluorescent membrane marker di-4-ANEPPS, and then arrested with high-K + Tyrode for either 2-photon microscopy (n=4) or MRI (n=4). Image analysis software was developed to extract SL at the cell level from >1,400 2-photon images (Fig 1 ) and correct for cell angle. SL increased by 10±2 % between 30 and 80 min of perfusion (1.98±0.04 to 2.17±0.03 μm; p<0.05; Fig 1 ). Measurements of left ventricular myocardial volume (LVMV) were made in vivo and in perfused hearts using 3D MRI. LVMV increased by 24±7% from in vivo to 30 min of perfusion, and by 11±3 % between 30 and 90 min (539±35; 664±44; 737±49 mm 3 , respectively; p<0.05; Fig 1 ). We show that SL can be measured in isolated perfused hearts. The method allowed monitoring of changes in SL over time, and showed that SL and LVMV increase to a similar extent during 30–80 min perfusion with crystalloid solution, probably due to tissue oedema. This result, together with the increase in LVMV during the first 30 min, highlights the pronounced differences between in vivo , in situ , and in vitro model systems for studies of cardiac physiology and mechanics. Future research will compare changes in SL in healthy hearts and disease models involving contractile dysfunction. Figure 1: Left: 2-photon microscopy image of di-4-ANEPPS labeled myocardium. Right: SL and LVMV changes over time.

scholarly journals In Vivo Sarcomere Length Measurement in Whole Muscles during Passive Stretch and Twitch Contractions

2017 ◽  
Vol 112 (4) ◽  
pp. 805-812 ◽  
Author(s):  
Kevin W. Young ◽  
Bill P.-P. Kuo ◽  
Shawn M. O’Connor ◽  
Stojan Radic ◽  
Richard L. Lieber
Keyword(s):  
Sarcomere Length ◽  
Length Measurement ◽  
Passive Stretch

Effect of sarcomere length on total capillary length in skeletal muscle: In vivo evidence for longitudinal stretching of capillaries

1990 ◽  
Vol 40 (1) ◽  
pp. 63-72 ◽  
Author(s):  
C.G. Ellis ◽  
O. Mathieu-Costello ◽  
R.F. Potter ◽  
I.C. MacDonald ◽  
A.C. Groom
Keyword(s):  
Skeletal Muscle ◽  
Sarcomere Length ◽  
Capillary Length

Regulation of glycogenolysis in human muscle at rest and during exercise

1982 ◽  
Vol 53 (3) ◽  
pp. 708-715 ◽  
Author(s):  
D. Chasiotis ◽  
K. Sahlin ◽  
E. Hultman
Keyword(s):  
Glycogen Phosphorylase ◽  
Total Activity ◽  
Human Muscle ◽  
Phosphorylase Activity ◽  
Michaelis Constant ◽  
Bicycle Exercise ◽  
Muscle Phosphorylase ◽  
Glycogen Utilization ◽  
Main Factors

The regulation of glycogenolysis in human muscle during isometric and dynamic exercise has been investigated. Total glycogen phosphorylase and synthase activities were unchanged during exercise. The fraction of phosphorylase in the alpha form at rest was estimated to be 20%, but the data indicate that the in vivo activity was low and critically dependent on the concentration of inorganic phosphate (Pi) in the muscle. Phosphorylase alpha increased initially 2.4-fold during isometric contraction and 1.6-fold during maximal bicycle exercise but reverted to or below the resting value at fatigue/exhaustion. At rest synthase I was 1713;48% of the total activity but decreased during exercise to about half of this value. The reciprocal changes in phosphorylase and synthase correlate with the enhanced rate of glycogenolysis during exercise. Michaelis constant (Km) for Pi was 27 mmol . l-1 for phosphorylase alpha and 7 mmol . l-1 for alpha + b. From consideration of the changes in Pi during exercise (to 20–30 mmol . l–1) it was concluded that Pi is one of the main factors determining phosphorylase activity and provides a link between phosphocreatine breakdown and glycogen utilization in muscle.

scholarly journals Defining the limits to efficiency in human muscle in vivo

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Frank Edward Nelson ◽  
Kevin Conley ◽  
Martin Kushmerick
Keyword(s):  
Human Muscle
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