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Bioscience, Biotechnology, and Biochemistry Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tbbb20
Effect of Exercise on Tissue Protein Synthesis in Rats a
ab
Kazutoshi Hayase & Hidehiko Yokogoshi a
Department of Home Economics, Aichi University of Education, Kariya, Aichi 448, Japan b
Laboratory of Nutritional Biochemistry, School of Food and Nutritional Sciences, The University of Shizuoka, Shizuoka 422, Japan Published online: 12 Jun 2014.
To cite this article: Kazutoshi Hayase & Hidehiko Yokogoshi (1992) Effect of Exercise on Tissue Protein Synthesis in Rats, Bioscience, Biotechnology, and Biochemistry, 56:10, 1637-1639, DOI: 10.1271/bbb.56.1637 To link to this article: http://dx.doi.org/10.1271/bbb.56.1637
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Biosci. Biotech. Biochem., 56 (10), 1637-1639, 1992
Effect of Exercise on Tissue Protein Synthesis in Rats Kazutoshi
HAYASE t
and Hidehiko
YOKOGOSHI*
Department of Home Economics, Aichi University of Education, Kariya, Aichi 448, Japan of Nutritional Biochemistry, School of Food and Nutritional Sciences, The University of Shizuoka, Shizuoka 422, Japan Received May 7, 1992
Downloaded by [University of Illinois Chicago] at 11:46 08 December 2014
* Laboratory
The effect of exercise on the protein metabolism in skeletal muscles (gastrocnemius and soleus), liver and small intestine was investigated in rats. Treadmill treatment for 7 d resulted in atrophy of the liver and small intestine, which was associated with a reduction in protein content. The rates of protein synthesis in the liver and small intestine were significantly suppressed in rats subjected to exercise. The change in protein synthesis in the visceral organs was mediated by the change in RNA activity (protein synthesis per unit RNA) but not by the change in RNA concentration. The tissue weight and the rate of protein synthesis in the gastrocnemius and soleus muscles were not affected by exercise. The results suggest that these changes in protein synthesis in the liver and small intestine may explain, at least partly, the atrophy of these organs which was observed after 7 d of exercise.
There has recently been considerable investigation into whether exercise changes protein turnover, but there is no consistent answer to the question. Widely varying results on the effect of exercise on protein synthesis in skeletal muscle have been reported, and there is no consensus as to the changes in muscle protein synthesis. Rennie et al. 1 ) and Dohm et al. 2 ) have reported that the incorporation of 14C-tyrosine into muscle protein was reduced after acute exercise in the perfused hindquarter and in vivo. Davis et al.,3) however, suggested that exercise training had no effect on protein synthesis in isolated muscle tissue. In the visceral organs, exercise was found to elevate protein degradation and decrease the protein contents in the liver. 4) In our previous study, prolonged hypokinetic conditions such as suspension resulted in an increase of hepatic protein synthesis,5) while little is known whether exercise affects protein synthesis in the liver and other visceral organs. The purpose of the present study is to determine whether exercise changes protein synthesis in the skeletal muscles and visceral organs (liver and small intestine). Three indicators of protein synthesis, its rates, RNA concentration and RNA activity, in the liver, small intestine and muscles were determined in rats subjected to exercise for 7 d. The animals in the experimental group exercised on a motor-driven treadmill. The protein synthesis in tissues was determined immediately after the last exercise to avoid the effect of diurnal rhythm on the tissue protein synthesis.
were kept at 24°C with a cycle of 12hr light (8:00 p.m.-8:00 a.m.) and 12 hr dark (8:00 a.m.-8:00 p.m.). The rats were transferred to the experimental diet after feeding with a non-purified commercial diet*2 for 5d. The composition of the experimental diet is given in Table I, and all rats were provided with food ad libitum. Experimental design. Twelve rats were divided into two groups and fed with the experimental diet for 7 d. During the experimental period, the rats in the experimental group exercised on a motor-driven treadmill at 17 m per min for I hr every day (1 :00 a.m.-2:00 p.m.). The control rats were not subjected to the treadmill. At the end of the experimental period, the rats were decapitated and blood was collected in glass tubes. The liver, small intestine, and the gastrocnemius and soleus muscles wer~ rapidly removed and frozen in liquid N 2. The small intestine was slit longitudinally after rinsing with cold saline, and a jejunal segment comprising the second 20 cm from the pyrolus was cut out. The effects of exercise on the rates of protein synthesis, RNA concentration and RNA activity (protein synthesis per unit RNA) in each tissue were then investigated. Analytical procedure. The fractional rates of protein synthesis in the liver, small intestine, and soleus and gastrocnemius muscles were measured by the large dose method of Garlick et al. 6 ) immediately after the last period of exercise. Radioactive L-[4- 3 H] phenylalanine was mixed with unlabeled phenylalanine to obtain a dose of 1.85 MBq and a concentration of 150 J.lmol/ml in 0.9% NaCl. The rats were injected with the radioactive solution at a dose of 1ml/lOO g of body weight via the tail vein. Ten min after injection, the rats were quickly decapitated. Determination of the specific radioactivity of protein-bound and free
Table I.
Composition of the Basal Diet Amount (%)
Ingredient Casein Corn starch Sucrose Corn oil AIN-76'Mineral mix b AIN-76A Vitamin mix b Choline chloride
20.0 46.9 23.4 5.0 3.5
Q
Q
Materials and Methods
Q
Chemicals. L-Tyrosine decarboxylase, phenethylamine and leucylalanine were purchased from Sigma Chemical Co. (St. Louis, MO, U.S.A.), and L-[4- 3 H] phenylalanine was obtained from Amersham Japan (Tokyo, Japan). All other reagents were products of Wako Pure Chemical Industries (Osaka, Japan). Q
Animals and diets. Young male rats of the Wistar strain*1 (6o-70g) t
*1 *2
b
1.0
0.2
Supplied by Oriental Yeast Co., Tokyo, Japan. Supplied by Nihon Nosan Kogyo, Yokohama, Japan. 14 .1S )
Address for correspondence: Department of Home Economics, Aichi University of Education, Kariya, Aichi 448, Japan. Japan SLC, Hamamatsu, Japan. MF; Oriental Yeast Co., Tokyo, Japan:
NII-Electronic Library Service
K. HAYASE and H. YOKOGOSHI
1638
phenylalanine involved its enzymatic conversion to phenethylamine, radioactivity counting*3 and fluorometric determination. *4 The protein content was measured by the procedure of Lowry et al. 7) The concentration of RNA was measured by the method of Munro and Fleck,8) while the plasma concentration of urea was measured according to the method of Archibald. 9) Statistical analysis. All data are expressed as means and standard deviation of means. Statistical analyses were performed by using Student's t-test,10) and differences are considered significant at p < O.OS.
Results
Downloaded by [University of Illinois Chicago] at 11:46 08 December 2014
The effects of exercise on body weight gain and tissue weights are presented in Table II. The gain of body weight and food intake were not affected by the exercise. When examined after 7 d of exercise, the weights of the liver and small intestine were significantly reduced in the rats Table II. Effects of Exercise on the Changes in Body Weight and Tissue Weightsa,b
Changes in body weight (g/7 d) Food intake (g/d) Liver weight (g/100 g of body weight) Small intestine weight (g/20 cm S.I. C) Gastrocnemius muscle weight (g/100 g of body weight) Soleus muscle weight (g/lOO g of body weight) a
b C
34.6±2.4 11.8±0.9 4.09±0.20
29.8±4.9 10.9 ± 1.1 3.71 ±0.24*
0.78±0.04
0.69±0.02*
1.00±0.07
0.99±0.09
0.OS2 ± 0.006
0.OS3 ± O.OOS
Effects of Exercise on the Composition of Tissues and Plasma
Plasma urea (mg/ml) Protein Liver (mg/liver weight for 100 g B.W.) Small intestine (mg/20cm S.I. b) Gastrocnemius muscle (mg/muscle weight for 100 g B.W.) Soleus muscle (mg/muscle weight for 100 g B.W.) RNA/Protein, Liver (mg/g of protein) Small intestine (mg/g of protein) Gastrocnemius muscle (mg/g of protein) Soleus muscle (mg/g of protein)
b
Exercise
Values are means±S.D. for six rats. *p
Bioscience, Biotechnology, and Biochemistry Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tbbb20
Effect of Exercise on Tissue Protein Synthesis in Rats a
ab
Kazutoshi Hayase & Hidehiko Yokogoshi a
Department of Home Economics, Aichi University of Education, Kariya, Aichi 448, Japan b
Laboratory of Nutritional Biochemistry, School of Food and Nutritional Sciences, The University of Shizuoka, Shizuoka 422, Japan Published online: 12 Jun 2014.
To cite this article: Kazutoshi Hayase & Hidehiko Yokogoshi (1992) Effect of Exercise on Tissue Protein Synthesis in Rats, Bioscience, Biotechnology, and Biochemistry, 56:10, 1637-1639, DOI: 10.1271/bbb.56.1637 To link to this article: http://dx.doi.org/10.1271/bbb.56.1637
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
Biosci. Biotech. Biochem., 56 (10), 1637-1639, 1992
Effect of Exercise on Tissue Protein Synthesis in Rats Kazutoshi
HAYASE t
and Hidehiko
YOKOGOSHI*
Department of Home Economics, Aichi University of Education, Kariya, Aichi 448, Japan of Nutritional Biochemistry, School of Food and Nutritional Sciences, The University of Shizuoka, Shizuoka 422, Japan Received May 7, 1992
Downloaded by [University of Illinois Chicago] at 11:46 08 December 2014
* Laboratory
The effect of exercise on the protein metabolism in skeletal muscles (gastrocnemius and soleus), liver and small intestine was investigated in rats. Treadmill treatment for 7 d resulted in atrophy of the liver and small intestine, which was associated with a reduction in protein content. The rates of protein synthesis in the liver and small intestine were significantly suppressed in rats subjected to exercise. The change in protein synthesis in the visceral organs was mediated by the change in RNA activity (protein synthesis per unit RNA) but not by the change in RNA concentration. The tissue weight and the rate of protein synthesis in the gastrocnemius and soleus muscles were not affected by exercise. The results suggest that these changes in protein synthesis in the liver and small intestine may explain, at least partly, the atrophy of these organs which was observed after 7 d of exercise.
There has recently been considerable investigation into whether exercise changes protein turnover, but there is no consistent answer to the question. Widely varying results on the effect of exercise on protein synthesis in skeletal muscle have been reported, and there is no consensus as to the changes in muscle protein synthesis. Rennie et al. 1 ) and Dohm et al. 2 ) have reported that the incorporation of 14C-tyrosine into muscle protein was reduced after acute exercise in the perfused hindquarter and in vivo. Davis et al.,3) however, suggested that exercise training had no effect on protein synthesis in isolated muscle tissue. In the visceral organs, exercise was found to elevate protein degradation and decrease the protein contents in the liver. 4) In our previous study, prolonged hypokinetic conditions such as suspension resulted in an increase of hepatic protein synthesis,5) while little is known whether exercise affects protein synthesis in the liver and other visceral organs. The purpose of the present study is to determine whether exercise changes protein synthesis in the skeletal muscles and visceral organs (liver and small intestine). Three indicators of protein synthesis, its rates, RNA concentration and RNA activity, in the liver, small intestine and muscles were determined in rats subjected to exercise for 7 d. The animals in the experimental group exercised on a motor-driven treadmill. The protein synthesis in tissues was determined immediately after the last exercise to avoid the effect of diurnal rhythm on the tissue protein synthesis.
were kept at 24°C with a cycle of 12hr light (8:00 p.m.-8:00 a.m.) and 12 hr dark (8:00 a.m.-8:00 p.m.). The rats were transferred to the experimental diet after feeding with a non-purified commercial diet*2 for 5d. The composition of the experimental diet is given in Table I, and all rats were provided with food ad libitum. Experimental design. Twelve rats were divided into two groups and fed with the experimental diet for 7 d. During the experimental period, the rats in the experimental group exercised on a motor-driven treadmill at 17 m per min for I hr every day (1 :00 a.m.-2:00 p.m.). The control rats were not subjected to the treadmill. At the end of the experimental period, the rats were decapitated and blood was collected in glass tubes. The liver, small intestine, and the gastrocnemius and soleus muscles wer~ rapidly removed and frozen in liquid N 2. The small intestine was slit longitudinally after rinsing with cold saline, and a jejunal segment comprising the second 20 cm from the pyrolus was cut out. The effects of exercise on the rates of protein synthesis, RNA concentration and RNA activity (protein synthesis per unit RNA) in each tissue were then investigated. Analytical procedure. The fractional rates of protein synthesis in the liver, small intestine, and soleus and gastrocnemius muscles were measured by the large dose method of Garlick et al. 6 ) immediately after the last period of exercise. Radioactive L-[4- 3 H] phenylalanine was mixed with unlabeled phenylalanine to obtain a dose of 1.85 MBq and a concentration of 150 J.lmol/ml in 0.9% NaCl. The rats were injected with the radioactive solution at a dose of 1ml/lOO g of body weight via the tail vein. Ten min after injection, the rats were quickly decapitated. Determination of the specific radioactivity of protein-bound and free
Table I.
Composition of the Basal Diet Amount (%)
Ingredient Casein Corn starch Sucrose Corn oil AIN-76'Mineral mix b AIN-76A Vitamin mix b Choline chloride
20.0 46.9 23.4 5.0 3.5
Q
Q
Materials and Methods
Q
Chemicals. L-Tyrosine decarboxylase, phenethylamine and leucylalanine were purchased from Sigma Chemical Co. (St. Louis, MO, U.S.A.), and L-[4- 3 H] phenylalanine was obtained from Amersham Japan (Tokyo, Japan). All other reagents were products of Wako Pure Chemical Industries (Osaka, Japan). Q
Animals and diets. Young male rats of the Wistar strain*1 (6o-70g) t
*1 *2
b
1.0
0.2
Supplied by Oriental Yeast Co., Tokyo, Japan. Supplied by Nihon Nosan Kogyo, Yokohama, Japan. 14 .1S )
Address for correspondence: Department of Home Economics, Aichi University of Education, Kariya, Aichi 448, Japan. Japan SLC, Hamamatsu, Japan. MF; Oriental Yeast Co., Tokyo, Japan:
NII-Electronic Library Service
K. HAYASE and H. YOKOGOSHI
1638
phenylalanine involved its enzymatic conversion to phenethylamine, radioactivity counting*3 and fluorometric determination. *4 The protein content was measured by the procedure of Lowry et al. 7) The concentration of RNA was measured by the method of Munro and Fleck,8) while the plasma concentration of urea was measured according to the method of Archibald. 9) Statistical analysis. All data are expressed as means and standard deviation of means. Statistical analyses were performed by using Student's t-test,10) and differences are considered significant at p < O.OS.
Results
Downloaded by [University of Illinois Chicago] at 11:46 08 December 2014
The effects of exercise on body weight gain and tissue weights are presented in Table II. The gain of body weight and food intake were not affected by the exercise. When examined after 7 d of exercise, the weights of the liver and small intestine were significantly reduced in the rats Table II. Effects of Exercise on the Changes in Body Weight and Tissue Weightsa,b
Changes in body weight (g/7 d) Food intake (g/d) Liver weight (g/100 g of body weight) Small intestine weight (g/20 cm S.I. C) Gastrocnemius muscle weight (g/100 g of body weight) Soleus muscle weight (g/lOO g of body weight) a
b C
34.6±2.4 11.8±0.9 4.09±0.20
29.8±4.9 10.9 ± 1.1 3.71 ±0.24*
0.78±0.04
0.69±0.02*
1.00±0.07
0.99±0.09
0.OS2 ± 0.006
0.OS3 ± O.OOS
Effects of Exercise on the Composition of Tissues and Plasma
Plasma urea (mg/ml) Protein Liver (mg/liver weight for 100 g B.W.) Small intestine (mg/20cm S.I. b) Gastrocnemius muscle (mg/muscle weight for 100 g B.W.) Soleus muscle (mg/muscle weight for 100 g B.W.) RNA/Protein, Liver (mg/g of protein) Small intestine (mg/g of protein) Gastrocnemius muscle (mg/g of protein) Soleus muscle (mg/g of protein)
b
Exercise
Values are means±S.D. for six rats. *p
