• Journal of Korean Academy of Nursing
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• v.28 no.4
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• pp.893-907
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• 1998

The purpose of this study was to determine the effect of regular exercise during dexamethasone injection on the body weight, weight of hindlimb muslces, myofibrillar protein content and glutamine synthetase activity. 180-200g female Wistar rats were divided into four groups : control, exercise, dexamethasone injection (dexa), and exercise during dexamethasone injection(D+E) group. The dexa group received daily subcutaneous injection of dexamethasone at a dose of 4mg/kg body weight for 7 days. The exercise group ran on a treadmill for 60min/day(20minutes every 4 hours) at 10m/min and a 10$^{\circ}$grade. The control group received daily subcutaneous injection of normal saline at a dose of 4mg/kg body weight for 7 days. The D+E group ran on a treadmill for 60min/day(20minutes every 4 hours) at 10m/min and a 10$^{\circ}$ grade during dexamethasone injection. Body weight of the control group increased significantly from days of experiment, that of the dexa group decreased significantly from day 4 of the experiment resulting in a 82.4% decrease compared to the first day of the experiment. Body weight of the D+E group decreased significantly from day 5 of experiment resulting in a 81.77% decrease comprared to the first day of the experiment. Body weights, muscle weight and myofibrillar protein content of the plantaris and gastrocnemius decreased significantly and muscle weight of the soleus tended to decrease with dexamethasone injection. Glutamine synthetase activity of the hindlimb muscles increased significantly with the dexamethasone injection. The relative weight of the soleus was comparable to the control group and that of plantaris decreased significantly and that of gastrocnemius tended to decrease compared to that of the control in the dexa group. Body weight and muscle weight of the plantaris and gastrocnemius of the excrcise group were comparable to the control group, and the muscle weight of soleus showed a tendencey to increase. The relative weight of the soleus increased significantly and that of the plantaris and gastrocnemius were comparable to the control in the exercise group. Myofibrillar protein content of the soleus and plantaris increased significantly and there was no change of GS activity of the hindlimb muscles compared to the control in the exercise group. Body weight of the D+E group was comparable to the dexa group, muscle weight of the plantaris increased significantly and that of the soleus and gastrocnemius showed a tendency to increase. The relative weight of the hindlimb muscles increased significantly. Myofibrillar protein content of the soleus and plantaris increased significantly and that of the gastrocnemius tended to increase compared to the dexa group. Body weight and muscle weight of the plantaris and gastrocnemius of the D+E group did not recover to that of the control group. Muscle weight of the soleus recovered to that of the control group. The relative weight and of myofibrillar protein content of the hindlimb muscles recovered to that of the control group. From these results, it is suggested that regular exercise during dexamethasone injection might attenuate the muscle atrophy of the hindlimb muscles.

• Journal of Korean Biological Nursing Science
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• v.4 no.1
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• pp.51-69
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• 2002

The purpose of this study was to identify the effect of cerebral ischemia on affected(Lt) and unaffected(Rt) side of soleus, plantaris and gastrocnemius muscle mass and determine the effect of exercise on affected and unaffected side on soleus, plantaris and gastrocnemius muscle mass during acute stage of stroke. Sixteen male Sprague-Dawley rate with 200-270g body weight were randomly divided into three groups: control, stroke, and exercise after stroke(St+Ex) group. The control group received sham operation and the stroke group and St+Ex group received transient right MCA(middle cerebral artery) occlusion operation. The St+Ex groups ran on a treadmill for 20min/day at 10m/min and $10^{\circ}$ grade for 6days. During the experimental period body weight and diet intake was measured every morning. On the 7th day after operation, muscles were dissected from both affected and unaffected side of hindlimb. Cerebral infarction of stroke and St+Ex groups were identified by staining with TCC for 30 minutes. The data were analyzed by Kruskal-Wallis test and Mann-Whitney U test using the SPSSWIN 9.0 program. Significance was accepted at the level of p<0.05. The results were summarized follows : 1) There were no significant difference of the body weight on the first day of experiment among 3 groups. Whereas on the 7th day, the body weight of both stroke group and St+Ex group were significantly smaller than that of control group. Body weight of St+Ex group on the 7th day tended to be larger than that of stroke group. 2) Total diet intake of both stroke group and St+Ex group were also significantly smaller than that of control group. While total amount of diet intake in St+Ex group tended to be larger than that of stroke group. 3) The weight of gastrocnemius muscle of affected side in stroke group significantly decreased compared to that of control group and the weight of soleus and plantaris muscle of affected side in stroke group tended to decrease compared to that of control group. 4) The weight of plantaris muscle of unaffected side in stroke group significantly decreased compared to that of control group and the weight of soleus and gastrocnemius muscle of unaffected side in stroke group tended to decrease compared to those of control group. 5) The weight of gastrocnemius muscle of affected side in stroke group significantly decreased compared to that of unaffected side and there was no significant difference of the weight of soleus and plantaris muscle in stroke group between affected side and unaffected side. 6) The weight of soleus, plantaris and gastrocnemius muscle of both affected side and unaffected side in St+Ex group had a tendency of increase compared to those of stroke group. The relative weight of soleus and gastrocnemius muscle of affected side and soleus muscle of unaffected side in St+Ex group had a tendency to increase compared to those of stroke group. Based on these results, exercise during acute stage of stroke might attenuate muscle atrophy of both affected and unaffected side of hindlimb muscles.

• Physical Therapy Korea
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• v.9 no.1
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• pp.17-42
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• 2002

The purpose of this study was to investigate the treatment effect of three interventions on the disuse atrophy of rat hindlimb after two weeks suspension. Forty-eight 11~12 weeks old female Sprague-Dawley white rats were divided into four intervention groups: 1) suspension only (S; n=10), 2) intensive weight bearing treadmill (IWBT; n=10), 3) electrical stimulation (ES; n=9), 4) 2)+3) (ES/IWBT; n=9). Another 10 rats received no intervention or hindlimb suspension and served as controls (C). After the interventions, 1) the cross-sectional area (CSA), 2) the ratio of white muscle fiber composition (WMFC), 3) isometric tetanic tension (ITT), and 4) muscle weights (MWs) were measured from the four calf muscle specimens. The results were as follows: 1. In all intervention groups, the CSAs of medial and lateral gastrocnemius (MG LG), soleus (SOL), and flexor digitorum superficialis (FDS) decreased when compared to the control (C) group (p<.05). The CSA increased in FDS and LG for the IWBT group, in SOL for the ES/IWBT group compared to the S only group (p<.05). 2. The ratios of WMFC in MG, LG, SOL, and FDS increased compared to the C group for all interventions (p<.05). The ratios of WMFC decreased in SOL and LG for the IWBT group, in SOL for the ES/IWBT group compared to the S only group, and decreased in SOL for the ES/IWBT group compared to the IWBT group (p<.05). 3. The ITT in the MG, LG, SOL, and FDS decreased compared to the C group for all interventions (p<.05). The ITT increased in MG LG/FDS, SOL, and the whole calf muscles (WCMs) in the IWBT, ES and ES/IWBT groups compared to the S only group (p<.05). 4. The MWs in MG LG/FDS, SOL, WCMs decreased compared to the C group for all interventions (p<.05). The MWs increased in MG LG/FDS and WCMs for the IWBT group, in SOL for the ES group, and in SOL for the ES/IWBT group compared to the S only group (p<.05). 5. In atrophied muscles, the IWBT group showed the best recovery and the ES/IWBT and ES groups followed in decreasing order. The most susceptible muscle to disuse atrophy was the SOL. But conversely, it showed the best recovery in the ES/IWBT group. After two weeks of hindlimb suspension, the calf muscles of rats atrophied and their isometric tension decreased. These changes were best reversed by hindlimb-focused treadmill activity. The next best results were achieved by electrical stimulation combined with the treadmill followed by only electrical stimulation. These findings indicate that full weight bearing treadmill activity alone or in combination with electrical stimulation are effective treatments for non-weight bearing induced muscle atrophy. Further study of the effect of different intensities of electrical stimulation and variations in the duration period of full weight bearing treadmill activity on disuse atrophy is recommended.