scholarly journals Influence of Hindlimb Unweighting and Intermittent Weight Bearing on Dynamics of Nuclei in Rat Soleus Muscle

2003 ◽  
Vol 6 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Toshiaki Yamazaki
Keyword(s):  
Soleus Muscle ◽  
Weight Bearing ◽  
Hindlimb Unweighting ◽  
Rat Soleus Muscle

Influence of chronic stretching upon rat soleus muscle during non-weight-bearing conditions

1994 ◽  
Vol 429 (2) ◽  
pp. 274-279 ◽  
Author(s):  
Damien Leterme ◽  
Corinne Cordonnier ◽  
Yvonne Mounier ◽  
Maurice Falempin
Keyword(s):  
Soleus Muscle ◽  
Weight Bearing ◽  
Rat Soleus Muscle

Time course of soleus muscle myosin expression during hindlimb suspension and recovery

1987 ◽  
Vol 63 (1) ◽  
pp. 130-137 ◽  
Author(s):  
D. B. Thomason ◽  
R. E. Herrick ◽  
D. Surdyka ◽  
K. M. Baldwin
Keyword(s):  
Protein Expression ◽  
Soleus Muscle ◽  
Time Course ◽  
Weight Bearing ◽  
Relative Proportion ◽  
Contractile Protein ◽  
Myosin Isoforms ◽  
Hindlimb Unweighting ◽  
Loss Of Weight ◽  
Myofibril Protein

This study examined the time course of adult rodent soleus muscle myofibril and myosin isoform protein expression after 4, 8, 16, 28, and 56 days of hindlimb unweighting by tail suspension (S). The time course of soleus muscle recovery (R) was also examined after 28 days of hindlimb unweighting with an additional 4, 8, 16, and 28 days of unrestricted cage activity. During suspension, soleus muscle myofibril protein rapidly decreased from 34.3 +/- 3.1 (1.96SE) mg/pair in the control (C) group to 6.9 +/- 1.4 (1.96SE) mg/pair in S (t = 56 days). The calculated first-order degradation rate constant for this loss was kd = 0.17 days-1 [half time (t1/2) = 4.1 days]. The estimated slow myosin (SM) isoform content decreased from 13.4 +/- 2.0 (1.96SE) mg/pair in C to 2.1 +/- 0.2 (1.96SE) mg/pair in S (kd = 0.19 days-1, t1/2 = 3.6 days). The relative proportion of other myosin isoforms was increased at 28 and 56 days of suspension, reflecting an apparent de novo synthesis and the loss of SM. Recovery of contractile protein after 28 days of suspension was slower for both the myofibril protein and the SM isoform (kd = 0.07 days-1, t1/2 = 10 days). These data suggest that loss of weight bearing specifically affected the mechanisms of contractile protein expression reflected in soleus muscle protein degradation processes. In addition, the expression of the myosin isoforms were apparently differentially affected by the loss of weight-bearing activity.

Distribution of myosin heavy chain isoforms in non-weight-bearing rat soleus muscle fibers

1996 ◽  
Vol 81 (6) ◽  
pp. 2540-2546 ◽  
Author(s):  
Robert J. Talmadge ◽  
Roland R. Roy ◽  
V. Reggie Edgerton
Keyword(s):  
Myosin Heavy Chain ◽  
Soleus Muscle ◽  
Heavy Chain ◽  
De Novo ◽  
Weight Bearing ◽  
Muscle Fibers ◽  
Myosin Heavy Chain Isoforms ◽  
Hindlimb Suspension ◽  
Type I ◽  
Rat Soleus Muscle

Talmadge, Robert J., Roland R. Roy, and V. Reggie Edgerton.Distribution of myosin heavy chain isoforms in non-weight-bearing rat soleus muscle fibers. J. Appl. Physiol. 81(6): 2540–2546, 1996.—The effects of 14 days of spaceflight (SF) or hindlimb suspension (HS) (Cosmos 2044) on myosin heavy chain (MHC) isoform content of the rat soleus muscle and single muscle fibers were determined. On the basis of electrophoretic analyses, there was a de novo synthesis of type IIx MHC but no change in either type I or IIa MHC isoform proportions after either SF or HS compared with controls. The percentage of fibers containing only type I MHC decreased by 26 and 23%, and the percentage of fibers with multiple MHCs increased from 6% in controls to 32% in HS and 34% in SF rats. Type IIx MHC was always found in combination with another MHC or combination of MHCs; i.e., no fibers contained type IIx MHC exclusively. These data suggest that the expression of the normal complement of MHC isoforms in the adult rat soleus muscle is dependent, in part, on normal weight bearing and that the absence of weight bearing induces a shift toward type IIx MHC protein expression in the preexisting type I and IIa fibers of the soleus.

Mechanisms of flow and ACh-induced dilation in rat soleus arterioles are altered by hindlimb unweighting

2002 ◽  
Vol 92 (3) ◽  
pp. 901-911 ◽  
Author(s):  
William G. Schrage ◽  
Christopher R. Woodman ◽  
M. Harold Laughlin
Keyword(s):  
Weight Bearing ◽  
Combined Treatment ◽  
Sprague Dawley ◽  
Hindlimb Unweighting ◽  
First Order ◽  
Sprague Dawley Rats ◽  
Independent Mechanism ◽  
Rat Soleus Muscle ◽  
Luminal Flow ◽  
Oxide Synthase

The purpose of this study was to test the hypothesis that endothelium-dependent dilation (flow-induced dilation and ACh-induced dilation) in rat soleus muscle arterioles is impaired by hindlimb unweighting (HLU). Male Sprague-Dawley rats (∼300 g) were exposed to HLU or weight-bearing control (Con) conditions for 14 days. Soleus first-order (1A) and second-order (2A) arterioles were isolated, cannulated, and exposed to step increases in luminal flow at constant pressure. Flow-induced dilation was not impaired by HLU in 1A or 2A arterioles. The cyclooxygenase inhibitor indomethacin (Indo; 50 μM) did not alter flow-induced dilation in 1As or 2As. Inhibition of nitric oxide synthase (NOS) with N ω-nitro-l-arginine (l-NNA; 300 μM) reduced flow-induced dilation by 65–70% in Con and HLU 1As. In contrast, l-NNA abolished flow-induced dilation in 2As from Con rats but had no effect in HLU 2As. Combined treatment with l-NNA + Indo reduced tone in 1As and 2As from Con rats, but flow-induced dilation in the presence of l-NNA + Indo was not different from responses without inhibitors in either Con or HLU 1As or 2As. HLU also did not impair ACh-induced dilation (10−9-10−4 M) in soleus 2As.l-NNA reduced ACh-induced dilation by ∼40% in Con 2As but abolished dilation in HLU 2As. Indo did not alter ACh-induced dilation in Con or HLU 2As, whereas combined treatment withl-NNA + Indo abolished ACh-induced dilation in 2As from both groups. We conclude that flow-induced dilation (1As and 2As) was preserved after 2 wk HLU, but HLU decreased the contribution of NOS in mediating flow-induced dilation and increased the contribution of a NOS- and cyclooxygenase-independent mechanism (possibly endothelium-derived hyperpolarizing factor). In soleus 2As, ACh-induced dilation was preserved after 2-wk HLU but the contribution of NOS in mediating ACh-induced dilation was increased.

Differential response of macrophage subpopulations to soleus muscle reloading after rat hindlimb suspension

1994 ◽  
Vol 77 (1) ◽  
pp. 290-297 ◽  
Author(s):  
B. A. St Pierre ◽  
J. G. Tidball
Keyword(s):  
Soleus Muscle ◽  
Weight Bearing ◽  
Recovery Process ◽  
Wistar Rat ◽  
Hindlimb Suspension ◽  
Muscle Necrosis ◽  
Macrophage Subpopulations ◽  
Rat Soleus Muscle ◽  
Developmental Myosin Heavy Chain ◽  
Immunohistochemical Techniques

The hypothesis that distinct populations of macrophages are associated with muscle necrosis and regeneration was examined in Wistar rat soleus muscle after 10 days of hindlimb suspension and 2, 4, and 7 days after the resumption of weight bearing. Necrosis was identified using histological features, such as muscle fiber infiltration, and regeneration was identified using immunohistochemical techniques for developmental myosin heavy chain (dMHC). Light-microscopic observations show that necrotic fibers in 2-day reloaded soleus muscle were invaded by ED1+ and Ia+ macrophages. The number of invaded fibers in muscles reloaded for 2 days increased to 2.8/mm2 compared with 0.2/mm2 in age-matched normal muscle but returned to control values by the 4th day of resumed weight bearing. In the interstitial spaces of 2-day recovery muscle, ED1+ and Ia+ macrophages numbered 369 and 332/mm2, respectively, compared with 12 and 72/mm2, respectively, in control soleus. After 7 days of reloading, the number of ED1+ cells was similar to that of control. Ia+ macrophages decreased to 240/mm2 at 4 days but after 7 days rose above control values to 429/mm2. ED2+ macrophages in 4- and 7-day reloaded soleus increased 70–80% in the interstitial spaces compared with control but were not observed to infiltrate necrotic muscle fibers at any time points. Immunohistochemistry and immunoblots using a monoclonal anti-dMHC antibody demonstrate a greater proportion of myofibers expressing dMHC isoforms after 4 and 7 days of reloading. These findings indicate that macrophage subpopulations are associated with distinct stages during the recovery process from hindlimb suspension: ED1+ macrophages are associated with muscle necrosis, whereas ED2+ cells are associated with muscle regeneration.(ABSTRACT TRUNCATED AT 250 WORDS)

Ontogenetic, gravity-dependent development of rat soleus muscle

2001 ◽  
Vol 280 (4) ◽  
pp. C1008-C1016 ◽  
Author(s):  
Yoshinobu Ohira ◽  
Takato Tanaka ◽  
Tomoo Yoshinaga ◽  
Fuminori Kawano ◽  
Takeshi Nomura ◽  
...  
Keyword(s):  
Soleus Muscle ◽  
Weight Bearing ◽  
Postnatal Period ◽  
Hindlimb Unloading ◽  
Full Weight Bearing ◽  
Type I ◽  
Myosin Isoforms ◽  
Normal Transition ◽  
Postural Muscle ◽  
Rat Soleus Muscle

We tested the hypothesis that rat soleus muscle fiber growth and changes in myosin phenotype during the postnatal, preweaning period would be largely independent of weight bearing. The hindlimbs of one group of pups were unloaded intermittently from postnatal day 4 to day 21: the pups were isolated from the dam for 5 h during unloading and returned for nursing for 1 h. Control pups were either maintained with the dam as normal or put on an alternating feeding schedule as described above. The enlargement of mass (∼3 times), increase in myonuclear number (∼1.6 times) and myonuclear domain (∼2.6 times), and transformation toward a slow fiber phenotype (from 56 to 70% fibers expressing type I myosin heavy chain) observed in controls were inhibited by hindlimb unloading. These properties were normalized to control levels or higher within 1 mo of reambulation beginning immediately after the unloading period. Therefore, chronic unloading essentially stopped the ontogenetic developmental processes of 1) net increase in DNA available for transcription, 2) increase in amount of cytoplasm sustained by that DNA pool, and 3) normal transition of myosin isoforms that occur in some fibers from birth to weaning. It is concluded that normal ontogenetic development of a postural muscle is highly dependent on the gravitational environment even during the early postnatal period, when full weight-bearing activity is not routine.

Insulin effects in denervated and non-weight-bearing rat soleus muscle

1990 ◽  
Vol 13 (7) ◽  
pp. 593-600 ◽  
Author(s):  
Marc E. Tischler ◽  
Soisungwan Satarug ◽  
Steven H. Eisenfeld ◽  
Erik J. Henriksen ◽  
Sara B. Rosenberg
Keyword(s):  
Soleus Muscle ◽  
Weight Bearing ◽  
Rat Soleus Muscle

Role of weight-bearing function on expression of myosin isoforms during regeneration of rat soleus muscles

1996 ◽  
Vol 270 (3) ◽  
pp. C763-C771 ◽  
Author(s):  
X. A. Bigard ◽  
D. Merino ◽  
B. Serrurier ◽  
F. Lienhard ◽  
Y. C. Guezennec ◽  
...  
Keyword(s):  
Soleus Muscle ◽  
Weight Bearing ◽  
Muscle Fibers ◽  
Immunohistochemical Analysis ◽  
Normal Weight ◽  
Hindlimb Suspension ◽  
Myosin Isoforms ◽  
Homogeneous Population ◽  
Postural Load ◽  
Rat Soleus Muscle

The expression of myosin isoforms was studied in regenerated rat soleus muscle during either normal or altered postural activity. Regeneration was induced following injury by venom from the Notechis scutatus scutatus snake. Immunohistochemical analysis showed that, in regenerating soleus muscle after 3 wk of hindlimb suspension, nearly all fibers reacted positively with the myosin heavy chain (MHC) antibody associated with fast-twitch muscle fibers (fast MHC). When 3 wk of recovery with normal weight-bearing activity followed hindlimb suspension, the regeneration soleus muscle exhibited a nearly homogeneous staining with the MHC antibody associated with the slow-twitch muscle fibers (slow MHC). These findings were in accordance with quantitative analysis of the electrophoretic separation of the native myosin isoforms. Immunohistochemical data showed that removal of weight bearing in the 21-day old regenerated soleus muscles resulted in an increase in fast MHC expression. Together, the results of the present study clearly demonstrate that the postural load is an important component in the induction of slow MHC in regenerating muscle and that the control of the expression of MHC in muscle comprising a homogeneous population of fibers deriving from satellite cells appears more homogeneous and more complete than in a nondegenerated one.

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