The effect of strenous exercise
on alanine concentration invenous plasma
Shigeru Yamada, Yoshio Kurodal)r'partment o[ Sports Sciences, College o{ Arts andSciences, University of Tokyo

Abstract'1'he effect of strenous exercise on the alanine concentration in venous blood plasma was studied.

Adult male subjects were exerciserl by use of a bicycle ergometer. Blood samples of the subjects wcrc
collected from an anticubilal vein and analyzed for plasma amino acid concentraLions.

Alanine concentration in venous blood showed increasing tendency after exercise. This increment
however, was not statisticall)'significant. Urea concentration in serum was not affected Ly exercise.

However. alanine concenlrirlion in venous bl<xrd after exercise is correlated with alanile concentrali()nin venous blood before excrcise. Difference of alanine concentmtion between before and after exer,:isecorrelated with branched-chain amino acid concentration in venous blood plasma before exercise.
It rvas suggested that alaninc formation was induced by uptake of branched-chain amino acirls ar:ddegradation trf protein itt strr rrous exercisr'.

Ke!'W'ords: Alanine; Brarchcd'chairl anifio acid: Strenous eaercise

Introduction
Recent studies have demonstrated that blrx glucose plays an important role as the feul sul:strateof skeletal muscle durirrg exercise. Maintenance of glucose homecxtasis in prolongecl cxercise lecessi'
tates an increase in tlte rate of gluconeogenesis. Sevetal recent reports indicated that exercise may(2) (3),and Sluconeogenesis(a) (s).
increase the levels of nitrogen excretion(r), amino acid oxidation
Since increased protein break down and increased amino acid utlization dttring exercise coukl alter
the concentrations of free amino acids in tissues and in plasma, we have investigatcd the effcct ofstrenous excrcise on Iree amino acid levels in plasma. In this study, young malcs werc sultjected trr
the strenous exercise by use of a bicycle ergometer and their blood samples were analized for tlte frcc

amino acid concentrations. We also determined the urea concentration in plasma which may reflect
the totll body protein metabolism.
MethodeSubject : Six healthy males, the university students of physical education participated as the experimental subjects. Physical characteristics of the subjects are given in Table 1. The experiment wasperformed in the morning after an overnight fast.
Procerlure: The exercise was carried out b1, rrse of a bicycle ergometer (N{onark). Thc subjects
exercised at 1 kp Ior 2 min. by bicycle ergometer rvith zrn increase <.rI work Ioad of 0.5 kp pcr min.
rvirh pedaling frequency c,f 50 rcvr.rlution per mirrurc.

Oxygen and carbon dioxide concentration were analyzed by SANEI expired gas analyser 1 H 02,Expired gas during pedaling was collected every mirrute by Douglas bag method. Electroc.rrdiogram
was recorded by chest unipolar leading. Ileart rate was counted every minure.

In the resting state and immediately after exercise Teflon catheter was inserted io aoticubital veinand blood sample of 5 ml was collected from each subject. Blood was deproteinized with sullosalicylic
acid and amino acids concentralions in plasma *ere determined by the automated ioo-exchange chro-matography (JLC-8AH amino acid analyzcr),
Results
Changes in oxygen uptake durirrg erercise are shown in Fig. 1. Oxygen uptake increasecl lir.rearly

wirh the increase oI work loa<I. N{eau oxygen uptake and heart rate {or all subjects wer e 22g? ml/min
and 173 beats/min, respectiYely.

The levels of amino acids concentration in venous blood plasma obtained before ald after exercise
are shown in Table 2 and Fig. 2-4.

The mean concentration ol individual amino acids before exercise are indicatcrl in Fig. 2, Themean concentration of indiviclual amino acids after exercise:rre indicated in Fig. 3. 'i'hc concentrationoI each amino acids before and after exercise were comlxrred. As shown in Fig. 4, corrcentrations ofalanine and arginine rose slightly after exercise. Ho\reler these iucrements were not statistically signi-Iicant. The level of branched'chain amino acid concentration alter exercise declined slightly than t[atTeble. I
Subjects

Age

Physical charactelistics of subjects,

Hei8htWeight(Cnl)

(kg)

li. I

Runine time Heart rate
at exerci.e.min)(beats/min)

Y.S

165

58

129

8′ 05″

154

li. sY.O

168

61

129

7′ 56″

152

170

65

132

9′ oo″

164

s.o17317162641208′ 02″212

1288′ 00″

179

S.Y
Mean8′ 10″

3belore exercise. lJrea concentration in plasma did not change by exercise, as shown in Fig. 5. The
work-dependent change in the serum alanine concentration significantly correlated with branched chainamino acid concentration in venous plasma before exercise (Fig. 6). Alanine concentration in venous
blood alter exercise correlated with alarrine concentration in venous plasma before exercise (Fig. 7).

Discuesion

In the pre.sent study, it is shown rhat alanine concentration in venous plasma increases slightly after
exercise but this increment is not statistically sigrrificant. Alanine is lornred by the transamination ofglutamate and pyruvate through a rclcrion caralyzed by alanine aminotransferase (6). Goldberg et al.
have shown that the amino group ftrr alanine synthesis in muscle is derived {rom the catabolism of
the branched-chain amino acids (leucirre, isoleucine and valine) (7). Accumulation of branched-chainamino acids would lead to an increase in glutamate and subsequently to a release of alanine by ir
linked transamination (8).

In the present study, the level of branched-chain amino acids in venous plasma slightly declined
after exercise.

Furthermore, this decline of branche-chain amino acids is correlated with increment oI alanine
concentration after exercise.

It is also suggested that amino group of alanine lormation derived branched-chain amino acids inblood.

Urea production is a reflectiot of total body protein metatolism. Urea concentration in plasma,ノ20001︵匡 ＼ ︻日 ︶口︼く 卜 ヽＯ
Ｚ 口 ●´ Ｘ ０SubieCtsYS ̲YO XXS O ― ―S.Y C―REST

123456Fig. l

Changes in oxygen uptake during errcise

Table, 2 Amino acid concertration before and after erercise running
Y SAmino acid pmol/l

Y0R Maftcr

afterafter

SY

SO

beforeTatl

188

217

382

283

391

391

392

353

664

292

Urea

5748

6028

4545

5000

5909

5688

2168

2023

5967

13524

Asp

40

38

50

4151

50

33

44

41

55

Asn
Clu
Cin
Pro
Cly
Ara

70

81

61

62

61

59

50

51

75

140

257

243

109

116

155

168

130

163

256

525

480

667

578

511

345

323

736

687

589

849

204

203

189

161

394

415

190

183

1311

444

346

868

319

302

327

337

245

252

391

708

500

606

271

329

411

533

354

441

573

817

26

25

22

21

19

18

13

12

33

57

Val

281

286

226

219

258

278

222

188

360

654

Met

36

33

35

34

28

27

25

27

52

83

lleu

76

80

68

63

87

89

63

58

101

206

Lcu

174

180

143

139

159

159

136

123

187

386

ryr

69

70

77

72

62

68

69

66

120

205

Phc

90

100

86

88

82

89

66

63

94

186

Orn

188

181

123

124

118

109

90

78

162

295

Lys

212

223

275

275

182

197

161

156

283

555

His

113

121

98

87

96

94

85

87

133

228

Arg

75

85

129

148

111

121

103

109

169

310

α―A― nbThI

198

194

168

153

183

193

122

115

256

439

Ser

209

206

172

161

169

170

128

117

209

436

ｒｌｌ
確 ｏｏ．

1目門簡聖堂so LQ
日高Fig. 2 Amino acid concentration before exercise

ψｍ″ｌ∞- gP-

P\ !....t r*

I\ pr," n", r!g :vl"t o-1.".sFig. 3 Amino acid concentration aft€r exercise

HiS Ileu

Tau

Fig. 4

Ditference of amino acid concentration in plasma between before and alter exercise'日 Ｈ
berore larterl.:■ ‐■:■ :￨￨￨￨￨￨￨￨ヽ STSR、lYOsosY

Fif. 5 Chanees in Urea before and after exercise.
″nol″

/250r

200「ｏ僣 ｏ■●Ｋｏ ︼ｏ一﹄０ 一●/／・ｏ﹄ｏ﹁Ｘ¨40or‑00,/

500

600

700

800

9oopnotft
l'ig.l6lBranched chain amino acid concentrarion hefore enercise

υ﹄
ｏ︼Ｃｏ
●ＬＯｏ一¨︶００Ｌ■●ィ﹁０めｏスｏ﹄ｏ´´¨﹄ ●０一:r ,r3(10 .100 5rt0

ri|0

Fis. 7 Amino acid concentration hefore e\ercise

serum or sweat has been reported to jncrease during excrcise b). some investigators (9) (10) (11).
These results suggest thc possibilir)' of increasecl protein breakdown during exercist'. In some cases,
horvever, argument has arisen that the site of protein catabolism may lot lle muscle. Ahlborg et 41.
have shown that there is an increased outpuL of branchecl-chiiin amino acids from the splanchnic becl

during prolonged light-intcnsity exercise (12).
In the present studt rlrcr concentralion in serum increased slightly after exercisc but this increaseis also statistically insignificrnt.

Urrder the prolonged Iight-intersitl' rvork, the concentr.tions in plasma of many amino acids'including alanine, tend to {all, \yllereas those o{ tlre branched-cbain amino acids rise. When thc
exercise is of moderate to healv intcnsity (600, i'O, mnx or grerter) but of short duration, theplasma level of amino nitrogen, alanine and branched-chain amino acids increase. During work o{longer duration (2 hours), horvcver, the concentrations of amino nitrogen, total amino acicl andbranched-chain amino acids decline. In the present study, exercise received by the subjects is of lightto heavy intensity and o{ short duration. Under the present condition, however, alanine, branchedchain amino acids in serum did not show any statisticaliy signi6cant increment a{ter exercise. Therefore, further detailed experiments may be nessesary to clali{y effect of exercise on alanine synthesis.
R€ference

1. Bere, A., and J. Keul: Serum alanine dLrring lasting phvsical erercise lnt J Sporis. Med l : 199 202' 1980
2. I-ernon, P. trV. R., and J. P, Nluliin : F]ffect of inirial muscte glycogen levels on protein catalmlism durine exercise.
.I. Appl. Physiol. 18 : 624 629, 19803. Dohn, G. L., -\. L. HccLer, W. l'l. Brorn, G. l. Khin, F. R P ente, li W Askerv andG R' P'eecher: Adaptation of Protein metabolism to enduran.e training. Biochem J' 164 : 705 708' 1!77
4. Felis. P : The glucose-alanine cyclc. Metaholism 22 | 179 2A7 ' $73
5. Felig. P: Amino acid meta|olism in c\ercise' Ann N Y Acad' Sci 301 : 56 €3' 1977

8

6. Garltr, A. J., I. E. Karl and Kipnis: Alanin: anC glutamine synthesis and release from skeletal muscle.the precursor role of amino acids in alanine and glutamine synthesis. l. Biol. chem 251 :836-843,1976
7. Chug, T. 1V., and A. I-. Goldterg: -l'he origin of alanine produced in skeletal muscle. I. Biol. chem. 253 : 3677
3384,1978

8. Ruderman, N. B: Muscle amino acid metabolism and sluconeosenesis. Ann, Rev, Med. 26 , 2450258, tg?s
9. Decombaz, 1., P. Reinhardt, K. Anantharaman, C. von Glutz, and J. R. Poortmans : Biochemical changes in a 100km run : Free amino acids urea and creatinine. Eur. J. Appl. Physiol. 41 | 6t-72. \g7g
10. Goodman, M. N., and J. lU. I.owenste;n: The purine nucteotide cycle. Studies of ammonia producrion by skeletel
muscle in situ and in Frfused preparations. J. Biol. Chem. 252:5051 50:0,1977.
i 1. Haralambie, G., and A. Ilerg : Serum urca and amino nitrosen changes s'irh erercise duration. Eur. J. Appl.
Physiol. 35 : 39 48, i97d

12. Ahlborg, G., P. Felig, L. Hagenteldt, It. Ilendlcr, and -1. Wahren: Subsrrare turnover during prolonsed exercisein man. l. Clin. Invcst. 53, 1080-1090. 1971

13. Calsten, A., 1). Ha)lgren, li. Jagenb rg, A. SvrnMrg, and I-. Werko: Arreriat concentrations of free fatty acids
and free amino acids in healthy humnn indiv ualsrt rest and at different sork loads. Scand. -1. Clin. LaL. Invest.
185-191, 1962.

14. Rennie, M. J., It. H. T. Ildwards, C. T. M. Davies, S. Krywarvych, D Hrlliday, l. C. Waterlow, and D. J. MiltNard: Protein nnd amino rcid turnover during and after exercise. Biochem. Soc. 't'rans. 8 : 499 501,1980
i5. Refsum, H. tt., L. Ii. Gjessing, and S. B. Srromme: Changes in plasma amino acid distribution and urine aminoacids excrction during prolonged heavy exercirc. n:and. J. Cl;n. Invest. 39 : 407 413, 1979.