Evaluation of an in vitro muscle contraction model in mouse primary cultured myotubes

2016 ◽  
Vol 497 ◽  
pp. 36-38 ◽  
Author(s):  
Yasuko Manabe ◽  
Shinya Ogino ◽  
Miyuki Ito ◽  
Yasuro Furuichi ◽  
Mayumi Takagi ◽  
...  
Keyword(s):  
Muscle Contraction ◽  
Cultured Myotubes

Abstract 15255: Statins Augment Circulating MicroRNA-499-5p Release With Muscle Contraction and Aerobic Exercise

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Pil-Ki Min ◽  
Joseph Park ◽  
Stephanie Isaacs ◽  
Beth A Taylor ◽  
Paul D Thompson ◽  
...  
Keyword(s):  
Muscle Contraction ◽  
Muscle Injury ◽  
Fold Change ◽  
C2c12 Myotubes ◽  
Circulating Microrna ◽  
Cultured Myotubes ◽  
Exercise Induced ◽  
Statin Use

Background: Statins exacerbate exercise-induced skeletal muscle injury. Muscle-specific microRNAs (myomiRs) increase in plasma after prolonged exercise, but the patterns of myomiRs release after statin-associated muscle injury have not been examined. Objectives: We examined the relationships among statin exposure, in vitro and in vivo muscle contraction, and candidate circulating myomiRs expression. Methods: We measured plasma levels of the myomiRs, circulating microRNA-1 (c-miR-1), c-miR-133a, c-miR-206 and c-miR-499-5p, from 28 statin-using and 28 non-statin using runners before (PRE), immediately after (FINISH), and 24 hours after a 42 km footrace (POST-24). We subsequently used contracting mouse C2C12 cultured myotubes with and without statin exposure to compare intracellular and extracellular expression of these molecules. Fold-changes of microRNAs are presented as median [interquartile range]. Results: In marathoners, c-miR-1, c-miR-133a, and c-miR-206 increased at FINISH, returned to baseline at POST-24, and were unaffected by statin use. In contrast, c-miR-499-5p was unchanged at FINISH in both groups, but c-miR-499-5p increased in statin users at the POST-24 time point compared to PRE [2.9 (1.3, 8.6) vs. 1.0 fold change, p <0.001] and to non-statin using runners [2.9 (1.3, 8.6) vs. 1.4 (0.9, 3.2) fold change, p < 0.05]. In cultured C2C12 myotubes, intracellular levels of candidate myomiRs remained stable except for modest declines of miR-1 and miR-206 with isolated myotube contraction (carbachol exposure) or simultaneous statin and myotube contraction. Extracellular miR-1, 133a, and 206 increased with contraction regardless of statin use. In contrast, extracellular miR-499-5p was unaffected by either isolated statin exposure or isolated contraction but increased with contraction + statin [4.8 (1.9, 8.1) vs. 1.0 (0.7, 1.5) fold change, p < 0.05 vs. control]. Conclusions: Statin-potentiated muscle injury during exercise is accompanied by augmented extracellular release of miR-499-5p. c-miR-499-5p may serve as a biomarker of statin-potentiated muscle damage.

Myogenic mechanism for peristalsis in the cat esophagus

1999 ◽  
Vol 277 (2) ◽  
pp. G306-G313 ◽  
Author(s):  
Harold G. Preiksaitis ◽  
Nicholas E. Diamant
Keyword(s):  
Muscle Contraction ◽  
Slow Wave ◽  
Circular Muscle ◽  
Smooth Muscle Contraction ◽  
Slow Waves ◽  
Mechanical Activity ◽  
Control Mechanisms ◽  
Slow Wave Oscillations

A myogenic control system (MCS) is a fundamental determinant of peristalsis in the stomach, small bowel, and colon. In the esophagus, attention has focused on neuronal control, the potential for a MCS receiving less attention. The myogenic properties of the cat esophagus were studied in vitro with and without nerves blocked by 1 μM TTX. Muscle contraction was recorded, while electrical activity was monitored by suction electrodes. Spontaneous, nonperistaltic, electrical, and mechanical activity was seen in the longitudinal muscle and persisted after TTX. Spontaneous circular muscle activity was minimal, and peristalsis was not observed without pharmacological activation. Direct electrical stimulation (ES) in the presence of bethanechol or tetraethylammonium chloride (TEA) produced slow-wave oscillations and spike potentials accompanying smooth muscle contraction that progressed along the esophagus. Increased concentrations of either drug in the presence of TTX produced slow waves and spike discharges, accompanied by peristalsis in 5 of 8 TEA- and 2 of 11 bethanechol-stimulated preparations without ES. Depolarization of the muscle by increasing K+ concentration also produced slow waves but no peristalsis. We conclude that the MCS in the esophagus requires specific activation and is manifest by slow-wave oscillations of the membrane potential, which appear to be necessary, but are not sufficient for myogenic peristalsis. In vivo, additional control mechanisms are likely supplied by nerves.

scholarly journals An In Vitro Contraction Model in Mouse Primary Cultured Myotubes Using Satellite Cells Originated from the EDL and Soleus Muscles

2016 ◽  
Vol 62 (Suppl.1) ◽  
pp. 143-143
Author(s):  
YASUKO MANABE ◽  
SHINYA OGINO ◽  
MIYUKI ITO ◽  
YASURO FURUICHI ◽  
MAYUMI TAKAGI ◽  
...  
Keyword(s):  
Satellite Cells ◽  
Cultured Myotubes

Mechanical loading regulates NOS expression and activity in developing and adult skeletal muscle

1998 ◽  
Vol 275 (1) ◽  
pp. C260-C266 ◽  
Author(s):  
James G. Tidball ◽  
Eliane Lavergne ◽  
Kim S. Lau ◽  
Melissa J. Spencer ◽  
James T. Stull ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Muscle Activation ◽  
Weight Bearing ◽  
No Production ◽  
Adult Skeletal Muscle ◽  
No Release ◽  
Cultured Myotubes ◽  
Passive Stretch ◽  
Expression And Activity

The hypothesis that changes in muscle activation and loading regulate the expression and activity of neuronal nitric oxide (NO) synthase (nNOS) was tested using in vitro and in vivo approaches. Removal of weight bearing from rat hindlimb muscles for 10 days resulted in a significant decrease in nNOS protein and mRNA concentration in soleus muscles, which returned to control concentrations after return to weight bearing. Similarly, the concentration of nNOS in cultured myotubes increased by application of cyclic loading for 2 days. NO release from excised soleus muscles was increased significantly by a single passive stretch of 20% or by submaximal activation at 2 Hz, although the increases were not additive when both stimuli were applied simultaneously. Increased NO release resulting from passive stretch or activation was dependent on the presence of extracellular calcium. Cyclic loading of cultured myotubes also resulted in a significant increase in NO release. Together, these findings show that activity of muscle influences NO production in the short term, by regulating NOS activity, and in the long term, by regulating nNOS expression.

Stimulatory phosphorylation of cAMP-specific PDE4D5 by contractile agonists is mediated by PKC-dependent inactivation of protein phosphatase 2A

2008 ◽  
Vol 294 (1) ◽  
pp. G327-G335 ◽  
Author(s):  
Karnam S. Murthy ◽  
Wimolpak Sriwai
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Okadaic Acid ◽  
Protein Phosphatase ◽  
Dependent Inactivation ◽  
Rhythmic Cycles ◽  
Phosphatase 2A ◽  
Contraction And Relaxation ◽  
Camp Levels

Smooth muscle of the gut undergoes rhythmic cycles of contraction and relaxation. Various constituents in the pathways that mediate muscle contraction could act to cross-regulate cAMP or cGMP levels and terminate subsequent relaxation. We have previously shown that cAMP levels are regulated by PKA-mediated phosphorylation of cAMP-specific phosphodiesterase 3A (PDE3A) and PDE4D5; the latter is the only PDE4D isoform expressed in smooth muscle. In the present study we have elucidated a mechanism whereby cholecystokinin (CCK) and, presumably, other contractile agonists capable of activating PKC can cross-regulate cAMP levels. Forskolin stimulated PDE4D5 phosphorylation and PDE4D5 activity. CCK significantly increased forskolin-stimulated PDE4D5 phosphorylation and activity and attenuated forskolin-stimulated cAMP levels. The effect of CCK on forskolin-induced PDE4D5 phosphorylation and activity and on cAMP levels was blocked by the inhibitors of PLC or PKC and in cultured muscle cells by the expression of Gαq minigene. The effects of CCK on PDE4D5 phosphorylation, PDE4D5 activity, and cAMP levels were mimicked by low (1 nM) concentrations of okadaic acid, but not by a low (10 nM) concentration of tautomycin, suggesting involvement of PP2A. Purified catalytic subunit of PP2A but not PP1 dephosphorylated PDE4D5 in vitro. Coimmunoprecipitation studies demonstrated association of PDE4D5 with PP2A and the association was decreased by the activation of PKC. In conclusion, cAMP levels are cross-regulated by contractile agonists via a mechanism that involves PLC-β-dependent, PKC-mediated inhibition of PP2A activity that leads to increase in PDE4D5 phosphorylation and activity and inhibition of cAMP levels.

scholarly journals In vitro muscle contraction force measurements on isolated and entire rat diaphragms

Critical Care ◽  
2010 ◽  
Vol 14 (Suppl 1) ◽  
pp. P204 ◽  
Author(s):  
C Armbruster ◽  
C Dassow ◽  
K Gamerdinger ◽  
J Guttmann ◽  
M Schneider ◽  
...  
Keyword(s):  
Muscle Contraction ◽  
Force Measurements ◽  
Contraction Force

The Influence of Insulin and Muscle Contraction on in vitro Glucose Transport

2008 ◽  
Vol 40 (Supplement) ◽  
pp. S243-S244
Author(s):  
Julia M. Santos ◽  
Sandra B. Ribeiro ◽  
Gloria Queiroz ◽  
José A. Duarte
Keyword(s):  
Muscle Contraction ◽  
Glucose Transport

Inhibitory and excitatory mechanisms of neurotensin action in canine intestinal circular muscle in vitro

1992 ◽  
Vol 70 (10) ◽  
pp. 1423-1431 ◽  
Author(s):  
F. Christinck ◽  
E. E. Daniel ◽  
J. E. T. Fox-Threlkeld
Keyword(s):  
Potassium Channels ◽  
Muscle Contraction ◽  
Intracellular Calcium ◽  
Contractile Activity ◽  
Circular Muscle ◽  
Membrane Resistance ◽  
Temperature Sensitive ◽  
Membrane Hyperpolarization ◽  
Neuromedin N

The effect of neurotensin on canine ileal circular muscle devoid of myenteric plexus was investigated using single and double sucrose gap techniques. Similar results were obtained with microelectrode techniques. Neurotensin caused a temperature-sensitive and dose-dependent biphasic response, an initial hyperpolarization associated with inhibition of contractile activity, followed by an excitatory phase, usually consisting of spike discharge and tonic and phasic contractions, for which depolarization was not required. Neither response was affected by tetrodotoxin, phentolamine, propranolol, or atropine. The hyperpolarization was associated with decreased membrane resistance, blocked by 10−7 M apamin, and converted to tonic depolarization by apamin (10−6 M). Tachyphylaxis to neurotensin occurred when the stimulation interval was less than 20 min. After Ca2+ depletion, depolarization was observed instead of the hyperpolarization; this depolarization was not affected by nitrendipine and was gradually abolished with repetitive stimulations at 20-min intervals. When Ca2+ was present, nifedipine did not alter the hyperpolarizing phase of the response but inhibited spiking and blocked all contractions. The excitatory phase of the response was enhanced by Bay K-8644. Neuromedin N elicited a response identical with that of neurotensin. The responses of the two peptides were completely cross tachyphylactic. Inhibitory junction potentials were not affected by neurotensin tachyphylaxis. It is concluded that neurotensin and neuromedin N activate apamin-sensitive, calcium-dependent potassium channels in circular muscle, causing membrane hyperpolarization and inhibition of muscle contraction. Release of intracellular calcium is involved in the activation of these potassium channels. When opening of potassium channels was inhibited, release of intracellular calcium caused depolarization. Neurotensin also activates L-type calcium channels, resulting in muscle contraction. Neurotensin does not appear to contribute to the compound inhibitory nerve response represented by the inhibitory junction potential.Key words: neurotensin, apamin, inhibitory junction potentials, ileum, circular muscle.

In vitro Effect of Amikacin on Rat and Human Detrusor Muscle Contraction

2008 ◽  
Vol 81 (1) ◽  
pp. 94-100
Author(s):  
M. Gardi ◽  
F. Nigro ◽  
E. Ragazzi ◽  
A. Volpe ◽  
A. Totaro ◽  
...  
Keyword(s):  
Muscle Contraction ◽  
Detrusor Muscle ◽  
Vitro Effect ◽  
Human Detrusor
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