Effect of anabolic/androgenic steroids on myosin heavy chain expression in hindlimb muscles of male rats

Noirez, Philippe; Ferry, Arnaud

doi:10.1007/pl00013789

Cited by 22 publications

(11 citation statements)

References 17 publications

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“…Because we preferred to use the single fibers for nitrotyrosine detection, it was not possible to determine myosin heavy chain (MHC) isoform composition of the single fibers. However, MHC isoform composition of rat soleus muscle consists almost exclusively of the slow isoform (12,(33)(34)(35). Therefore, it is very unlikely that nonuniform distribution of MHC isoform composition between fibers of different experimental groups has influenced the robust changes in single fiber contractility between groups, as observed in the present study.…”

Section: Nitrotyrosine Measurementmentioning

confidence: 58%

Hypoxia-induced skeletal muscle fiber dysfunction: role for reactive nitrogen species

Ottenheijm

Heunks

Geraedts

et al. 2006

American Journal of Physiology-Lung Cellular and Molecular Phys

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Hypoxia impairs skeletal muscle function, but the precise mechanisms are incompletely understood. In hypoxic rat diaphragm muscle, generation of peroxynitrite is elevated. Peroxynitrite and other reactive nitrogen species have been shown to impair contractility of skinned muscle fibers, reflecting contractile protein dysfunction. We hypothesized that hypoxia induces contractile protein dysfunction and that reactive nitrogen species are involved. In addition, we hypothesized that muscle reoxygenation reverses contractile protein dysfunction. In vitro contractility of rat soleus muscle bundles was studied after 30 min of hyperoxia (Po2 approximately 90 kPa), hypoxia (Po2 approximately 5 kPa), hypoxia + 30 microM N(G)-monomethyl-L-arginine (L-NMMA, a nitric oxide synthase inhibitor), hyperoxia + 30 microM L-NMMA, and hypoxia (30 min) + reoxygenation (15 min). One part of the muscle bundle was used for single fiber contractile measurements and the other part for nitrotyrosine detection. In skinned single fibers, maximal Ca2+-activated specific force (Fmax), fraction of strongly attached cross bridges (alphafs), rate constant of force redevelopment (ktr), and myofibrillar Ca2+ sensitivity were determined. Thirty minutes of hypoxia reduced muscle bundle contractility. In the hypoxic group, single fiber Fmax, alphafs, and ktr were significantly reduced compared with hyperoxic, L-NMMA, and reoxygenation groups. Myofibrillar Ca2+ sensitivity was not different between groups. Nitrotyrosine levels were increased in hypoxia compared with all other groups. We concluded that acute hypoxia induces dysfunction of skinned muscle fibers, reflecting contractile protein dysfunction. In addition, our data indicate that reactive nitrogen species play a role in hypoxia-induced contractile protein dysfunction. Reoxygenation of the muscle bundle partially restores bundle contractility but completely reverses contractile protein dysfunction.

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Section: Nitrotyrosine Measurementmentioning

confidence: 58%

Hypoxia-induced skeletal muscle fiber dysfunction: role for reactive nitrogen species

Ottenheijm

Heunks

Geraedts

et al. 2006

American Journal of Physiology-Lung Cellular and Molecular Phys

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“…Previous investigations have shown a direct effect of AAS treatment on muscle mass, contractile properties, and on the expression of myosin heavy-chain isoforms [13,16,17]. The results have demonstrated that a short period (6 weeks) of nandrolone decanoate treatment in the absence of exercise increases twitch tension and the sensitivity of the ryanodine receptor to caffeine at low concentrations tested, suggesting some modifications in the excitation-contraction coupling mechanism [16].…”

Section: Introductionmentioning

confidence: 74%

Nandrolone Decanoate Reduces Changes Induced by Hindlimb Suspension in Voltage-Dependent Tension of Rat Soleus Muscle

Bouhlel¹,

Joumaa²,

Léoty³

2003

Jpn.J.Physiol

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In skeletal muscles, the depolarization of action potentials in transverse tubules induces a movement of charged voltage sensors [1] within the dihydropyridine receptors [2]. The voltage sensors then activate the opening of Ca 2ϩ -release channels in the sarcoplasmic reticulum to generate tension. In order to look at the excitation-contraction coupling mechanism directly without complications of additional effects due to the action potential mechanism, potassium contractures were generally used rather than twitch-tension responses.Isometric tension generated by prolonged depolarization (K ϩ contracture) allows analysis of the relationship between myoplasmic calcium concentration or tension and T-tubule membrane potential, which has been shown to be different in slow-and fasttwitch fibers [3]. Thus, activation and inactivation processes involved in depolarization-contraction coupling can be examined in skeletal muscles using the K ϩ contracture technique [3][4][5].

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“…1997), myosin (Tsika et al . 1987) and MHC isoforms (Noirez & Ferry 2000) in fast‐twitch muscle. Further experiments are necessary to assess whether nandrolone decanoate treatment induces changes in the expression of troponin C isoforms.…”

Section: Discussionmentioning

confidence: 99%

Nandrolone decanoate treatment induces changes in contractile responses of rat untrained fast‐twitch skeletal muscle

Joumaa

Serrurier²,

Bigard³

et al. 2002

Acta Physiologica Scandinavica

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This investigation was designed to examine whether short-term administration of anabolic-androgenic steroids (AAS) (nandrolone decanoate) could produce changes in contractile responses of untrained rat fast- (edl) and slow- (soleus) twitch skeletal muscle. Twenty male rats were divided into two groups, one group received weekly (for 6 weeks) an intramuscular injection of AAS, nandrolone decanoate (15 mg kg(-1)) and the second group received weekly the similar doses of vehicle (sterile peanut oil). In edl intact isolated small bundles (two to four cells), it was found that nandrolone decanoate treatment increases the K+ contracture tension (146 mM) relative to maximum tension by 56%, whereas no change was observed in the time to peak tension and in the time constant of relaxation. By contrast, in treated soleus muscle, compared with control, no significant modification was found in the K+ contracture characteristics. The change in edl contractile responses was associated with a shift to more negative potential of the voltage-dependence activation and the steady-state inactivation curves which also shifted leftward in treated soleus fibres. Furthermore, in edl skinned Triton X-100 fibres, the Ca2+ sensitivity of contractile proteins (pCa50) was increased, while electrophoresis analysis indicates no significant effect of nandrolone decanoate treatment on myosin heavy chain (MHC) isoforms. The present results show that nandrolone decanoate treatment produces more pronounced changes in untrained fast muscle function rather than soleus by acting at different levels of the excitation-contraction coupling mechanism without changes in the MHC isoforms and that contractile responses became similar to those found in soleus muscle.

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Effect of anabolic/androgenic steroids on myosin heavy chain expression in hindlimb muscles of male rats

Cited by 22 publications

References 17 publications

Hypoxia-induced skeletal muscle fiber dysfunction: role for reactive nitrogen species

Hypoxia-induced skeletal muscle fiber dysfunction: role for reactive nitrogen species

Nandrolone Decanoate Reduces Changes Induced by Hindlimb Suspension in Voltage-Dependent Tension of Rat Soleus Muscle

Nandrolone decanoate treatment induces changes in contractile responses of rat untrained fast‐twitch skeletal muscle

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