Combined Effect of High Intensity Exercise and (-) Epigallocatechin-3-gallate of Green Tea Supplementation on Heme Oxygenase-1 in the Large Intestine of SD Rats / 대한스포츠의학회지

The purpose of this study was to investigate effects of combined treatment with high intensity exercise and (-) epigallocatechin-3 gallate (EGCG), a potent free radical scavenger on a transcriptional level of hemoxygenase-1 gene in the large intestine. Sprague-Dawley rats were randomly divided into control group (CON, n=7), high intensity exercise group (HIE, n=7), EGCG group (EGCG, n=7), and EGCG plus high intensity exercise group (HIE + EGCG, n=7). Animals were given an intraperitoneal injection of EGCG with 50 mg of dosage per kg for four weeks 30 minutes before exercise. In order to induce HIE animals were allowed to ran on a treadmill with 0 degree of slope at speed of 28 m/min for 30 minutes. The exercise was performed four times a week for four week. The results of this study were as following; The expression level of hemoxygenase-1 mRNA of the high intensity exercise group was 15.21 times higher than that of the control group. The EGCG plus high intensity exercise group showed 5.98 times increased expression level of hemoxygenase-1 mRNA than control group. These results suggest that treatment of EGCG decrease the expression level of HO-1 mRNA through the removal of oxygen radicals produced by a high intensity exercise.

Changes in the Gastrointestinal Motility following Unilateral Labyrinthectomy / 대한평형의학회지

BACKGROUND AND OBJECTIVES The temporal changes and the role of glutamate receptors in the recovery of vestibulogastrointestinal symptoms following unilateral labyrinthectomy (UL) were investigated in this study. Vestibulogastrointestinal symptoms were evaluated in terms of gastric emptying and intestinal transit. MATERIALS AND METHODS Expression of the c-Fos protein was observed in the solitary tract nucleus (STN) and rostral ventrolateral medullary nucleus (RVLM). These were measured at 0.5, 2, 6 and 24 h following UL in rats. RESULTS Gastric emptying and intestinal transit were significantly decreased for 6 h post UL and recovered to control levels within 24 h. Pretreatment of UL animals with MK-801 significantly increased the gastric emptying and intestinal transit. Bilateral labyrinthectomy significantly decreased the gastric emptying and intestinal transit compared to the intact labyrinthine animals but significantly increased when compared to UL animals. The expression of c-Fos protein was significantly increased in STN and RVLM compared to the control animals for 6 h post UL and recovered to control levels within 24 h. The expression was significantly decreased in animals that were pretreated with MK-801. CONCLUSION These results suggest that UL decreases the gastrointestinal motility, which recovers to control levels within 24 h post UL. Glutamate plays an important role in the recovery of vestibulogastrointestinal symptoms following UL.

Effect of graded running on esophageal motility and gastroesophageal reflux in fed volunteers

The effects of different grades of running on esophageal motility and gastroesophageal reflux in the fed state were evaluated. We studied healthy volunteers (male: 12, age: 27+/-5 yr) using ambulatory esophageal manometry, pH catheter and portable digital data recorder. Each exercise was performed 30 min after meal, with 20 min of rest between exercises. Subjects exercised on a treadmill at 40% and 70% maximal heart rate. The number of gastroesophageal reflux episodes, the duration of esophageal acid exposure and percent time pH below 4 were significantly (p<0.01) increased during exercise at 70% maximal heart rate. The frequency of contraction (contraction/min) (p<0.05), frequency of repetition (p<0.01), percent of simultaneous contraction (p<0.01), percent of above 100 mmHg amplitude (p<0.05), and frequency of 2-peak contraction (p<0.01) were significantly increased during exercise at 70% maximal heart rate. However, median amplitude and median duration showed no significant changes between each exercise session. Postprandial running exercises induce gastroesophageal reflux, which correlates with exercise intensity. These effects are mediated by disorganized esophageal motility.

Rhabdomyolysis and Changes of Biochemical Markers in the Long-Distance Runners / 대한신장학회잡지

BACKGROUND: Exercise has almost always been intuitively considered beneficial, but although rewards greatly outweigh risks, exercise occasionally produces bad or even fatal outcomes such as acute renal failure or sudden death. Exertional rhabdomyolysis has been occasionally reported in adult patients following such strenuous activities as military basic training, weight lifting, and marathon running. The purpose of the present study was to investigate whether exertional rhabdomyolysis developed, and how exercise could influence biochemical markers of rhabdomyolysis during resting, exercise, and recovery period in long-distance runners. METHODS: Twenty-four young long-distance runners who volunteered to participate in the study, trained with running over 200km every week for 2 to 3 years were studied. Levels of serum creatine kinase(CK), lactate dehydrogenase(LDH), asparatate amino-transferase (AST), and myoglobin, and urine myoglobin were measured at 24hr(pre-exercise period) before, immediately (post-exercise period), and at 24hr(recovery period) after 10km running. Ten long-distance runners who were randomly selected at 24hr after 10km running, including one complaining of calf pain, and age-matched nine young control students were subjected to bone scan with technetiun-99m methylene diphosphonate(99mTc-MDP) RESULTS: Serum CK activities in pre-exercise period were higher than that of the upper normal range. Serum CK and LDH activities were significantly increased in post-exercise period compared with pre-exercise period(p<0.05), were not decreased to the level of post- exercise in recovery period. The level of serum myoglobin was increased and decreased significantly,(p<0.05, p<0.01, respectively) and urine myoglobin and serum AST activities were remained within nomal range in each period. The mean uptake count of 99mTc-MDP in both lower extremities of runners was significantly greater than that of the control group(p<0.001), and had good correlation with the serum CK activities of post-exercise, and recovery period(r=0.87 p<0.001, r=0.8 p<0.01, respectively). CONCLUSION: This study suggests that rhabdomyolysis in the well trained long-distance runners may be developed in low grade, but ongoing injuries during each running. For the diagnosis of rhabdomyolysis in the well trained long-distance runners, serum CK levels are thought to be the most useful marker, and the cut- off value of serum CK levels should be lowered less than usual five times of normal value. A quantitative measurements of 99mTc-MDP uptake with serum CK levels can be more helpful in making the diagnosis of rhabdomyolysis in the well trained long-distance runners.

Effect of Running on Esophageal Motility and Gastroesophageal Reflux / 대한내과학회지

OBJECTIVES: Physical exercise has become popular in recent years. It has been known that exercise is related to the development of heartburn, belching, regurgitation and chest pain. However there are few data concerning the effect of exercise on esophageal motor function and gastroesophageal reflux. We evaluated the effect of exercise intensity on esophageal motor activity and gastroesophageal reflux. METHODS: We studied healthy volunteers (15 males, age: 28+/-5 years, BW: 68+/-10kg) using a 24 hours ambulatory esophageal pressure, pH catheter and portable digital data recorder (Microdigitrapper 4Mb, Synetics Medical, Sweden). Subjects exercised on a treadmill (Marquette Case 15 Electronic INC) at 50% and 70% maximal heart rate for 30 min. Subjects rested 2 hours before exercise (base line) and for 30 min between exercise sessions. RESULTS: 1) Exercise of 50% maximal heart rate reduced total contraction, contraction duration, percentage of simultaneous contraction and repetitive contraction, (P<0.05) but increased percentage of contractions above 20mmHg amplitude (P<0.05). 2) Exercise of 70% maximal heart rate decreased total contraction, esophageal amplitude, contraction duration and percentage of peristaltic contraction, (P<0.05) but increased percentage of simultaneous contraction (P<0.05). 3) Gastroesophageal reflux was not change on both 50% maximal heart rate and 70% maximal heart rate exercise. CONCLUSION: More propulsive esophageal motility are induced following exercise of 50% maximal heart rate, but not 70% maximal heart rate.

Mechanism of Electrical Stimulation on Functional Recovery Following Spinal Injury in Rats

The present study was designed to investigate the effects and action mechanism of electrical stimulation on functional recovery following spinal cord injury in Sprague-Dawley rats. Electrical stimulation with 0.2 ms, 20 Hz, 1-3 V was applied to the sciatic nerve for 4 hours/day during 6 days following dorsal hemisection of the T10 spinal cord. After 7 days of spinal cord injury, mechanical properties of muscle contraction including contraction time, half relaxation time, maximum twitch tension, maximum tetanic tension, and fatigue index were measured in the soleus and medial gastrocnemius muscles, and the number of c-fos immunoreactive cells was counted in the upper lumbar cord. In mechanical properties of muscle contraction of normal rats, contraction time and half relaxation time of the soleus muscle were 1.5 times and 2 times as long as those of the medial gastrocnemius muscle, respectively. And fatigue index of the soleus muscle was 0.19?0.4 and the medial gastrocnemius muscle was 0.82?0.03. According to the above characteristics, the soleus muscle was mainly composed of slow muscle fibers and the medial gastrocnemius muscle was composed of fast muscle fibers. Maximum twitch tension, maximum tetanic tension, and fatigue index of both muscles following spinal cord injury were decreased significantly compared to the control group (P<0.01). In electrically stimulated rats following spinal cord injury, maximum twitch tension, maximum tetanic tension, and fatigue index were significantly increased compared to spinal cord injured rats. The number of c-Fos immunoreactive cells was increased markedly at the upper lumbar cord in electrically stimulated rats. These results may suggest that electrical stimulation not only prevents from muscle atrophy in slow and fast muscles through efferent nerve fibers, but also promotes functional plasticity through afferent nerve fibers by activating silent synapse and regulation of receptors for neurotransmitters.