Microautoradiographic studies of glucose uptake in skeletal muscle fibers at rest

2001 ◽  
Vol 103 (4) ◽  
pp. 355-363 ◽  
Author(s):  
Hana Hayasaki ◽  
Masahisa Shimada ◽  
Kiyoto Kanbara ◽  
Masahito Watanabe
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Muscle Fibers ◽  
Skeletal Muscle Fibers

scholarly journals Fibroblast growth factor-21 potentiates glucose transport in skeletal muscle fibers

2020 ◽  
Vol 65 (3) ◽  
pp. 85-95
Author(s):  
G Rosales-Soto ◽  
A Diaz-Vegas ◽  
M Casas ◽  
A Contreras-Ferrat ◽  
E Jaimovich
Keyword(s):  
Skeletal Muscle ◽  
Growth Factor ◽  
Glucose Uptake ◽  
Fibroblast Growth Factor ◽  
Glucose Transport ◽  
Muscle Fibers ◽  
Fibroblast Growth Factor 21 ◽  
Fibroblast Growth ◽  
Skeletal Muscle Fibers ◽  
Pkc Ζ

Fibroblast growth factor 21 (FGF21) is a pleiotropic peptide hormone that is considered a myokine playing a role in a variety of endocrine functions, including regulation of glucose transport and lipid metabolism. Although FGF21 has been associated with glucose metabolism in skeletal muscle cells, its cellular mechanism in adult skeletal muscle fibers glucose uptake is poorly understood. In the present study, we found that FGF21 induced a dose−response effect, increasing glucose uptake in skeletal muscle fibers from the flexor digitorum brevis muscle of mice, evaluated using the fluorescent glucose analog 2-NBDG (300 µM) in single living fibers. This effect was prevented by the use of either cytochalasin B (5 µM) or indinavir (100 µM), both antagonists of GLUT4 activity. The use of PI3K inhibitors such as LY294002 (50 µM) completely prevented the FGF21-dependent glucose uptake. In fibers electroporated with the construct encoding GLUT4myc-eGFP chimera and stimulated with FGF21 (100 ng/mL), a strong sarcolemmal GLUT4 label was detected. This effect promoted by FGF21 was demonstrated to be dependent on atypical PKC-ζ, by using selective PKC inhibitors. FGF21 at low concentrations potentiated the effect of insulin on glucose uptake but at high concentrations, completely inhibited the uptake in the presence of insulin. These results suggest that FGF21 regulates glucose uptake by a mechanism mediated by GLUT4 and dependent on atypical PKC-ζ in skeletal muscle.

scholarly journals Fibroblast Growth Factor 21 Promotes Glucose Uptake in Adult Skeletal Muscle Fibers from Mice

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Giovanni Rosales‐Soto ◽  
Alexis Díaz‐Vegas ◽  
Paola Llanos ◽  
Enrique Jaimovich ◽  
Ariel Contreras‐Ferrat
Keyword(s):  
Skeletal Muscle ◽  
Growth Factor ◽  
Glucose Uptake ◽  
Fibroblast Growth Factor ◽  
Muscle Fibers ◽  
Fibroblast Growth Factor 21 ◽  
Fibroblast Growth ◽  
Adult Skeletal Muscle ◽  
Skeletal Muscle Fibers

The “KIMWIPE” Effect in Ultra-Thin Cryosections

1985 ◽  
Vol 43 ◽  
pp. 458-459
Author(s):  
I. Taylor ◽  
P. Ingram ◽  
J.R. Sommer
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Fibers ◽  
Ice Crystals ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Thin Sections ◽  
Skeletal Muscle Fibers ◽  
Freeze Dried ◽  
Ice Crystal Formation

In studying quick-frozen single intact skeletal muscle fibers for structural and microchemical alterations that occur milliseconds, and fractions thereof, after electrical stimulation, we have developed a method to compare, directly, ice crystal formation in freeze-substituted thin sections adjacent to all, and beneath the last, freeze-dried cryosections. We have observed images in the cryosections that to our knowledge have not been published heretofore (Figs.1-4). The main features are that isolated, sometimes large regions of the sections appear hazy and have much less contrast than adjacent regions. Sometimes within the hazy regions there are smaller areas that appear crinkled and have much more contrast. We have also observed that while the hazy areas remain still, the regions of higher contrast visibly contract in the beam, often causing tears in the sections that are clearly not caused by ice crystals (Fig.3, arrows).

Effect of External Calcium and other Divalent Cations on K+ Contractures in Denervated Slow Skeletal Muscle Fibers of the Frog

2019 ◽  
Author(s):  
Leonardo Hernández
Keyword(s):  
Skeletal Muscle ◽  
Binding Capacity ◽  
Divalent Cations ◽  
Muscle Fibers ◽  
Free Calcium ◽  
Slow Skeletal Muscle ◽  
Skeletal Muscle Fibers ◽  
Free Calcium Concentration ◽  
Chronic Denervation ◽  
Denervated Muscles

The influence of Ca2+ and other divalent cations on contractile responses of slow skeletal muscle fibers of the frog (Rana pipiens) under conditions of chronic denervation was investigated.Isometric tension was recorded from slow bundles of normal and denervated cruralis muscle in normal solution and in solutions with free calcium concentration solution or in solutions where other divalent cations (Sr2+, Ni2+, Co2+ or Mn2+) substituted for calcium. In the second week after nerve section, in Ca2+-free solutions, we observed that contractures (evoked from 40 to 80 mM-K+) of non-denervated muscles showed significantly higher tensions (p<0.05), than those from denervated bundles. Likewise, in solutions where calcium was substituted by all divalent cations tested, with exception of Mn2+, the denervated bundles displayed lower tension than non-denervated, also in the second week of denervation. In this case, the Ca2+ substitution by Sr2+ caused the higher decrease in tension, followed by Co2+ and Ni2+, which were different to non-denervated bundles, as the lowest tension was developed by Mn2+, followed by Co2+, and then Ni2+ and Sr2+. After the third week, we observed a recovery in tension. These results suggest that denervation altering the binding capacity to divalent cations of the voltage sensor.

scholarly journals Development of a human neuromuscular tissue-on-a-chip model on a 24-well-plate-format compartmentalized microfluidic device

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Kazuki Yamamoto ◽  
Nao Yamaoka ◽  
Yu Imaizumi ◽  
Takunori Nagashima ◽  
Taiki Furutani ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Microfluidic Device ◽  
Motor Neurons ◽  
Muscle Fibers ◽  
Three Dimensional ◽  
Tissue Model ◽  
Skeletal Muscle Fibers

A three-dimensional human neuromuscular tissue model that mimics the physically separated structures of motor neurons and skeletal muscle fibers is presented.

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