Dietary Creatine Monohydrate Supplementation Increases Satellite Cell Mitotic Activity During Compensatory Hypertrophy

2000 ◽  
Vol 21 (1) ◽  
pp. 13-16 ◽  
Author(s):  
B. Dangott ◽  
E. Schultz ◽  
P. E. Mozdziak
Keyword(s):  
Mitotic Activity ◽  
Satellite Cell ◽  
Compensatory Hypertrophy ◽  
Creatine Monohydrate

Muscle regeneration during hindlimb unloading results in a reduction in muscle size after reloading

2001 ◽  
Vol 91 (1) ◽  
pp. 183-190 ◽  
Author(s):  
P. E. Mozdziak ◽  
P. M. Pulvermacher ◽  
E. Schultz
Keyword(s):  
Mitotic Activity ◽  
Satellite Cell ◽  
Soleus Muscle ◽  
Weight Bearing ◽  
Weight Ratio ◽  
The Body ◽  
Hindlimb Unloading ◽  
Muscle Size ◽  
Unit Size ◽  
Muscle Weight

The hindlimb-unloading model was used to study the ability of muscle injured in a weightless environment to recover after reloading. Satellite cell mitotic activity and DNA unit size were determined in injured and intact soleus muscles from hindlimb-unloaded and age-matched weight-bearing rats at the conclusion of 28 days of hindlimb unloading, 2 wk after reloading, and 9 wk after reloading. The body weights of hindlimb-unloaded rats were significantly ( P < 0.05) less than those of weight-bearing rats at the conclusion of hindlimb unloading, but they were the same ( P > 0.05) as those of weight-bearing rats 2 and 9 wk after reloading. The soleus muscle weight, soleus muscle weight-to-body weight ratio, myofiber diameter, number of nuclei per millimeter, and DNA unit size were significantly ( P< 0.05) smaller for the injured soleus muscles from hindlimb-unloaded rats than for the soleus muscles from weight-bearing rats at each recovery time. Satellite cell mitotic activity was significantly ( P < 0.05) higher in the injured soleus muscles from hindlimb-unloaded rats than from weight-bearing rats 2 wk after reloading, but it was the same ( P > 0.05) as in the injured soleus muscles from weight-bearing rats 9 wk after reloading. The injured soleus muscles from hindlimb-unloaded rats failed to achieve weight-bearing muscle size 9 wk after reloading, because incomplete compensation for the decrease in myonuclear accretion and DNA unit size expansion occurred during the unloading period.

Myonuclear accretion is a major determinant of avian skeletal muscle growth

1997 ◽  
Vol 272 (2) ◽  
pp. C565-C571 ◽  
Author(s):  
P. E. Mozdziak ◽  
E. Schultz ◽  
R. G. Cassens
Keyword(s):  
Skeletal Muscle ◽  
Mitotic Activity ◽  
Satellite Cell ◽  
Muscle Development ◽  
Muscle Growth ◽  
Growth Potential ◽  
Unit Size ◽  
Skeletal Muscle Growth ◽  
Age Related ◽  
Related Increase

The role of satellite cells and DNA unit size in determining skeletal muscle growth was studied after mitotic activity was inhibited in the left pectoralis thoracicus of 2-wk-old tom turkeys by means of a 25-Gy dose of irradiation. Toms were killed and muscle weights were obtained 1 (n = 5), 4 (n = 6), 7 (n = 6), and 15 (n = 4) wk after irradiation. Satellite cell mitotic activity and DNA unit size were determined using enzymatically isolated myofiber segments and image analysis. Irradiated and nonirradiated muscle weights increased (P < 0.01) between all ages examined, but irradiated muscle weights were significantly (P < 0.01) lower than nonirradiated muscle weights at 4, 7, and 15 wk after irradiation. Satellite cell mitotic activity was lower (P < 0.01) in irradiated than in nonirradiated muscles at 1 and 4 wk after irradiation and resulted in a significant reduction (P < 0.05) in the number of myofiber nuclei per millimeter at 4 and 7 wk after irradiation. Satellite cell mitotic activity was higher (P < 0.05) in irradiated than in nonirradiated muscles at 7 wk after irradiation, but at 15 wk after irradiation it had fallen to low levels in both muscles. There was no significant (P > 0.10) difference in DNA unit size between muscles at any time, but there was an age-related increase (P < 0.01) for both muscles. Irradiation reduced muscle growth through a transient reduction in myonuclear production at a critical time (3-6 wk of age) in posthatch skeletal muscle development. The age-related increase in DNA unit size was not accelerated to compensate for the reduction in myonuclear accretion. Thus it appears that muscle growth potential is governed mostly by myonuclear accretion and to a lesser extent by DNA unit size.

scholarly journals Satellite Cell Mitotic Activity in Posthatch Turkey Skeletal Muscle Growth

1994 ◽  
Vol 73 (4) ◽  
pp. 547-555 ◽  
Author(s):  
P.E. MOZDZIAK ◽  
E. SCHULTZ ◽  
R.G. CASSENS
Keyword(s):  
Skeletal Muscle ◽  
Mitotic Activity ◽  
Satellite Cell ◽  
Muscle Growth ◽  
Skeletal Muscle Growth

Acute effects of hindlimb unweighting on satellite cells of growing skeletal muscle

1994 ◽  
Vol 76 (1) ◽  
pp. 266-270 ◽  
Author(s):  
E. Schultz ◽  
K. C. Darr ◽  
A. Macius
Keyword(s):  
Skeletal Muscle ◽  
Mitotic Activity ◽  
Satellite Cell ◽  
Satellite Cells ◽  
Extensor Digitorum Longus ◽  
Morphological Changes ◽  
Weight Bearing ◽  
Acute Effects ◽  
Hindlimb Unweighting ◽  
Growing Rat

The proliferative behavior of satellite cells in growing rat soleus and extensor digitorum longus muscles was examined at short periods after initiation of hindlimb unweighting. Mitotic activity of satellite cells in both muscles decreased below weight-bearing control levels within 24 h of initiation of hindlimb unweighting. This satellite cell response was > or = 48 h before any atrophic morphological changes that take place in the muscles. Suppression of mitotic activity was most severe in the soleus muscle where continuous infusion of label demonstrated that virtually all mitotic activity was abolished between 3 and 5 days. The results of this study suggest that satellite cell mitotic activity is a sensitive indicator of primary atrophic changes occurring in growing myofibers and may be a predictor of future morphological changes.

Unloading of juvenile muscle results in a reduced muscle size 9 wk after reloading

2000 ◽  
Vol 88 (1) ◽  
pp. 158-164 ◽  
Author(s):  
P. E. Mozdziak ◽  
P. M. Pulvermacher ◽  
E. Schultz
Keyword(s):  
Mitotic Activity ◽  
Satellite Cell ◽  
Soleus Muscle ◽  
Muscle Development ◽  
Weight Bearing ◽  
The Body ◽  
Muscle Size ◽  
Hindlimb Suspension ◽  
Unit Size ◽  
Muscle Weight

The role of satellite cells and DNA unit size in determining muscle size was examined by inhibiting postnatal skeletal muscle development by using hindlimb suspension. Satellite cell mitotic activity and DNA unit size were determined in the soleus muscles from hindlimb-suspended and age-matched weight-bearing rats before the initiation of hindlimb suspension, at the conclusion of a 28-day hindlimb-suspension period, 2 wk after reloading, and 9 wk after reloading. The body weights of hindlimb-suspended rats were significantly ( P < 0.05) less than those of weight-bearing rats at the conclusion of hindlimb suspension, but they were the same ( P > 0.05) as those of weight-bearing rats 9 wk after reloading. The soleus muscle weight, soleus muscle weight-to-body weight ratio, myofiber diameter, nuclei per millimeter, and DNA unit size for the hindlimb-suspended rats were significantly ( P < 0.05) smaller than for the weight-bearing rats at all recovery times. Satellite cell mitotic activity was significantly ( P < 0.05) higher in the soleus muscles from hindlimb-suspended rats 2 wk after reloading, but it was the same ( P > 0.05) as in weight-bearing rats 9 wk after reloading. Juvenile soleus muscles failed to achieve normal muscle size 9 wk after reloading because there was incomplete compensation for the hindlimb-suspension-induced interruptions in myonuclear accretion and DNA unit size expansion.

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