**5.2 The administration of glucose or sucrose in young and old men**

Blood was taken before the experiments from old men and amino acids levels were measured at 0 min and 120 min after the administration of glucose (15 men) or sucrose (16 men) or water as a control (13 men). Amino acids levels of all blood samples were measured. Compared with the control group, essential amino acids (EAAs) such as histidine, lysine, methionine, phenylalanine, threonine, tryptophan, leucine, isoleucine, and valine and branched amino acids (BAAs) such as leucine, isoleucine, and valine decreased significantly 120 min after the administration or glucose or sucrose in old men. Nonessential amino acid (NEAA) levels decreased at 120 min after the administration of glucose only compared with the control group.

In 36 young men, amino acids levels in plasma were measured at 0 min and 120 min after the administration of glucose (12 men) or sucrose (13 men), with 11 men of a control group taking water only. Similarly, the EAA and BCAA levels decreased in comparison with the control group (11 men) after the administration of glucose or sucrose to young men. EAAs such as histidine, lysine, methionine, phenylalanine, threonine, tryptophan, leucine, isoleucine, and valine and BCAAs such as leucine, isoleucine, and valine decreased significantly after the


**45**

*\*\*P < 0.01.*

**Table 2.**

*Glucose or Sucrose Intakes and Plasma Levels of Essential and Nonessential Amino Acids*

Histidine 78.5±7.7 78.7±7.5 Lysine 185.9±28.6 190.9±28.7 Methionine 27.3±3.6 27.6±4.9

Threonine 131.4±21.5 136.5±27.4 Tryptophan 65.8±9.1 58.7±9.2 Isoleucine 67.9±11.2 67.5±8.5 Leucine 129.8±16.8 133.8±17.5 Valine 221.9±16.3 228.1±30.6

Arginine 77.6±15.0 79.3±17.6 Asparagine 45.0±6.1 47.3±5.7 Aspartic acid 3.4±1.4 3.4±0.7

Glutamine 548.5±64.0 575.6±53.0 Glycine 213.5±25.9 198.5±28.6 Monoethanolamine 8.5±1.2 8.8±1.3

Proline 172.8±58.4 169.2±56.9

Total amino acids 2751.7±215 2891.4±201.6 Total essential AAs 695.3±89.0 985.4±94.9

Total branched chain AAs 419.5±48.3 427.5±52.3 Fisher ratio 3.7±0.4 3.2±0.4

**Amino acids Young men (n = 36) Old men (n = 44) ss**

Phenylalanine 56.9±7.0 65.4±8.8 \*\*

Tyrosine 58.2±8.7 70.3±12.0 \*\* Alanine 356.0±68.8 415.9±75.7 \*\* A-Aminobutyric acid 20.9±5.3 21.7±6.5 \*\*

Citrulline 22.2±3.6 27.0±6.2 \*\* Cysteine 14.1±4.1 23.6±6.7 \*\* Glutamic acid 37.0±11.6 45.0±16. \*\*

Ornithine 59.4±12.5 72.5±13.9 \*\*

Serine 124.6±17.2 105.5±18.2 \*\* Taurine 49.9±1.5 67.7±3.1 \*\*

Total nonessential AAs 1786.4±153.3 1960.4±166.0 \*\*

administration of glucose or sucrose in young groups too. NEAA levels decreased

In **Figure 1**, changes in the levels of total amino acids at 120 min in old and young men after the administration of glucose or sucrose were compared to those levels in the control group. When glucose was taken the amounts of total amino acids significantly decreased in young and aged people. Sucrose administration resulted in a significant decrease in the total amino acids only in old men (**Figure 1**).

after the administration of glucose in old and young men.

*Plasma levels of amino acids in young and old men in Japan (nM).*

*AAs: amino acids, ss: statistical significance.*

*DOI: http://dx.doi.org/10.5772/intechopen.92257*

#### **Table 1.** *Background of participants.*


*Glucose or Sucrose Intakes and Plasma Levels of Essential and Nonessential Amino Acids DOI: http://dx.doi.org/10.5772/intechopen.92257*

#### **Table 2.**

*New Insights into Metabolic Syndrome*

men take more carbohydrate.

were higher in young men.

control group.

amino acids between young and old men.

**5.1 Measurements of plasma levels of amino acids in old and young men**

**Table 1** shows the background of participants. There was no difference on energy intake between young and old men. Young men take more lipids and old

Levels of phenylalanine, tyrosine, alanine, A-aminobutyric acid, citrulline, cysteine, glutamic acid, ornithine, and taurine were higher in old men, and serine

Blood was taken before the experiments from old men and amino acids levels were measured at 0 min and 120 min after the administration of glucose (15 men) or sucrose (16 men) or water as a control (13 men). Amino acids levels of all blood samples were measured. Compared with the control group, essential amino acids (EAAs) such as histidine, lysine, methionine, phenylalanine, threonine, tryptophan, leucine, isoleucine, and valine and branched amino acids (BAAs) such as leucine, isoleucine, and valine decreased significantly 120 min after the administration or glucose or sucrose in old men. Nonessential amino acid (NEAA) levels decreased at 120 min after the administration of glucose only compared with the

In 36 young men, amino acids levels in plasma were measured at 0 min and 120 min after the administration of glucose (12 men) or sucrose (13 men), with 11 men of a control group taking water only. Similarly, the EAA and BCAA levels decreased in comparison with the control group (11 men) after the administration of glucose or sucrose to young men. EAAs such as histidine, lysine, methionine, phenylalanine, threonine, tryptophan, leucine, isoleucine, and valine and BCAAs such as leucine, isoleucine, and valine decreased significantly after the

**Subjects Young (n = 36) Old (n = 44) ss** Age (years) 20.8±1.6 62.4±9.6 \*\* Height (m) 1.72±0.06 1.68±0.07 \* BMI 22.2±3.3 24.3±3.2 \*

Lipid intake (g/day) 60.4±24.8 49.1±22.6 \* Carbohydrate intake (g/day) 78.9±13.1 198.6±89.4 \*\*

Energy intake(kcal/day) 1988±591.8 2115.1±460.2 Protein intake (g/day) 69.3±25.1 66.6±28.8

Insulin (μU/ml) 6.87±4.19 6.19±3.79

**5.2 The administration of glucose or sucrose in young and old men**

**Table 2** shows plasma levels of amino acids of young and old men. Plasma levels of nonessential amino acids were higher in old men than young men. No differences were shown in plasma levels of total amino acids, and total essential and branched

**5. Results**

**44**

*\* P<0.05. \*\*P<0.01.*

**Table 1.**

*Background of participants.*

*Plasma levels of amino acids in young and old men in Japan (nM).*

administration of glucose or sucrose in young groups too. NEAA levels decreased after the administration of glucose in old and young men.

In **Figure 1**, changes in the levels of total amino acids at 120 min in old and young men after the administration of glucose or sucrose were compared to those levels in the control group. When glucose was taken the amounts of total amino acids significantly decreased in young and aged people. Sucrose administration resulted in a significant decrease in the total amino acids only in old men (**Figure 1**).

Decrease in plasma levels of total essential amino acids at 120 min after the administration of solutions containing 50 g of glucose or sucrose in young and old men were calculated.

**Figure 2** shows changes in the decrease of total EAA levels at 120 min compared with the control group after glucose or sucrose administration in aged and young men. After the administration of both glucose and sucrose administration total EAAs significantly decreased in young and aged men at 120 min after the administration compared with the control group.

**Figure 3** shows decrease in total NEAA levels at 120 min compared with the control group after glucose or sucrose administration in aged men. Glucose intake resulted in a significant decrease in the amounts of total NEAA levels in aged men. There was practically no further decrease in the total NEAAs after the administration of sucrose compared with the control group in either old or young men.

*Changes in total amino acids after the administration of glucose or sucrose in young and old men.*

#### **Figure 2.**

*Changes in total essential amino acids levels after the administration of glucose or sucrose in young and old men.*

**47**

**6. Discussion**

**Figure 4.**

*old men.*

**Figure 3.**

*old men.*

compared with the control group.

brain or peripheral organs.

*Glucose or Sucrose Intakes and Plasma Levels of Essential and Nonessential Amino Acids*

**Figure 4** shows a decrease in the plasma levels of total BCAAs at 120 min after the administration of glucose or sucrose to old and young men. Both glucose and sucrose administrations significantly decreased total BCAA (leucine, isoleucine, and valine) levels in young and aged men at 120 min after the administration

*Changes in total branched chain amino acids after the administration of glucose or sucrose in young and* 

*Changes in total nonessential amino acids (NEAAs) after the administration of glucose or sucrose in young and* 

Is carbohydrate needed for the transportation of amino acids from blood to the

*DOI: http://dx.doi.org/10.5772/intechopen.92257*

*Glucose or Sucrose Intakes and Plasma Levels of Essential and Nonessential Amino Acids DOI: http://dx.doi.org/10.5772/intechopen.92257*

#### **Figure 3.**

*New Insights into Metabolic Syndrome*

tration compared with the control group.

men were calculated.

Decrease in plasma levels of total essential amino acids at 120 min after the administration of solutions containing 50 g of glucose or sucrose in young and old

**Figure 3** shows decrease in total NEAA levels at 120 min compared with the control group after glucose or sucrose administration in aged men. Glucose intake resulted in a significant decrease in the amounts of total NEAA levels in aged men. There was practically no further decrease in the total NEAAs after the administration of sucrose compared with the control group in either old or young men.

*Changes in total amino acids after the administration of glucose or sucrose in young and old men.*

*Changes in total essential amino acids levels after the administration of glucose or sucrose in young and* 

**Figure 2** shows changes in the decrease of total EAA levels at 120 min compared with the control group after glucose or sucrose administration in aged and young men. After the administration of both glucose and sucrose administration total EAAs significantly decreased in young and aged men at 120 min after the adminis-

**46**

**Figure 2.**

*old men.*

**Figure 1.**

*Changes in total nonessential amino acids (NEAAs) after the administration of glucose or sucrose in young and old men.*

#### **Figure 4.**

*Changes in total branched chain amino acids after the administration of glucose or sucrose in young and old men.*

**Figure 4** shows a decrease in the plasma levels of total BCAAs at 120 min after the administration of glucose or sucrose to old and young men. Both glucose and sucrose administrations significantly decreased total BCAA (leucine, isoleucine, and valine) levels in young and aged men at 120 min after the administration compared with the control group.

## **6. Discussion**

Is carbohydrate needed for the transportation of amino acids from blood to the brain or peripheral organs.

As indicated by Burtman's group [18, 19], insulin is needed for the transportation of tryptophan to the brain.

**Figure 5** illustrates the transportation of tryptophan from the blood to the brain. Insulin released upon intake of sugar facilitates the transportation of tryptophan. Burtman's group proposed that tryptophan competes with other long neutral amino acids for the transportation to the brain and that in the presence of insulin long neutral amino acids except for tryptophan are transported to the peripheral organ so that remaining tryptophan is now transported to the brain.

**Figure 6** shows the hypothesis that in the presence of insulin long neutral amino acids are mainly transported to the peripheral organs and tryptophan is now transported to the brain.

**Figure 5.** *The transportation of tryptophan from the blood to the brain.*

**49**

**Figure 7.**

*Glucose or Sucrose Intakes and Plasma Levels of Essential and Nonessential Amino Acids*

Intake of glucose or sucrose was shown to result in decrease in plasma levels of essential amino acids. Since insulin stimulate protein synthesis of the muscle [16] essential amino acids transported to the muscle are used muscular protein synthesis. This hypothesis explains why decrease in plasma levels of amino acids, especially essential amino acids after the administration of glucose or sucrose in

Tryptophan is important for the stability of emotion, sleep and satiety. There are many factors controlling hunger and satiety. As shown in **Figure 7**, ghrelin released from the stomach enhances foods intakes by stimulating NPY/AgRP NPY (neuropeptide Y)/AgRP (Agouti related peptide) in the arcuate nucleus. On the other hand PYY3–36 released from the colon inhibits NPY/AgRP. Leptin from fatty cells and insulin from the pancreas inhibit NPY/AgRP and stimulate melanocortin-producing cells. Serotonin and leucine have been proposed to inhibit hunger. In view of roles of tryptophan, thus serotonin in appetite controlling mecha-

Recently volumes and contents of intake amino acids are paid attention to.

Ensuring sufficient consumption of proteins is needed for growth, reproduction, and species survival [24]. Evolutionally animals had mechanisms to keep adequate protein intake. Detection of decrease or increase of single amino acids can

Hundred years ago, the marked reduction in energy intake and growth of animals maintained on diets containing very low protein amounts or imbalanced EAA ratios was first described. Harper and colleagues showed that the anorectic response to imbalanced amino acid diets is the cause rather than the consequence of growth failure. This suggestion supports the idea that dietary amino acids are important in

nisms, intakes of carbohydrates must be paid much attention.

**7. Sensing of amino acids in the central nervous system**

profoundly influence feeding behavior and food preference [24–27].

*DOI: http://dx.doi.org/10.5772/intechopen.92257*

men may be explained by this hypothesis.

*Central and peripheral mechanisms of food intakes.*

the regulation of food intake [28–31].

**Figure 6.** *Transportation of long neutral amino acids to the peripheral organs.*

*Glucose or Sucrose Intakes and Plasma Levels of Essential and Nonessential Amino Acids DOI: http://dx.doi.org/10.5772/intechopen.92257*

**Figure 7.** *Central and peripheral mechanisms of food intakes.*

*New Insights into Metabolic Syndrome*

tion of tryptophan to the brain.

transported to the brain.

As indicated by Burtman's group [18, 19], insulin is needed for the transporta-

**Figure 6** shows the hypothesis that in the presence of insulin long neutral amino acids are mainly transported to the peripheral organs and tryptophan is now

so that remaining tryptophan is now transported to the brain.

**Figure 5** illustrates the transportation of tryptophan from the blood to the brain. Insulin released upon intake of sugar facilitates the transportation of tryptophan. Burtman's group proposed that tryptophan competes with other long neutral amino acids for the transportation to the brain and that in the presence of insulin long neutral amino acids except for tryptophan are transported to the peripheral organ

**48**

**Figure 6.**

**Figure 5.**

*Transportation of long neutral amino acids to the peripheral organs.*

*The transportation of tryptophan from the blood to the brain.*

Intake of glucose or sucrose was shown to result in decrease in plasma levels of essential amino acids. Since insulin stimulate protein synthesis of the muscle [16] essential amino acids transported to the muscle are used muscular protein synthesis. This hypothesis explains why decrease in plasma levels of amino acids, especially essential amino acids after the administration of glucose or sucrose in men may be explained by this hypothesis.

Tryptophan is important for the stability of emotion, sleep and satiety.

There are many factors controlling hunger and satiety. As shown in **Figure 7**, ghrelin released from the stomach enhances foods intakes by stimulating NPY/AgRP NPY (neuropeptide Y)/AgRP (Agouti related peptide) in the arcuate nucleus. On the other hand PYY3–36 released from the colon inhibits NPY/AgRP. Leptin from fatty cells and insulin from the pancreas inhibit NPY/AgRP and stimulate melanocortin-producing cells. Serotonin and leucine have been proposed to inhibit hunger.

In view of roles of tryptophan, thus serotonin in appetite controlling mechanisms, intakes of carbohydrates must be paid much attention.

Recently volumes and contents of intake amino acids are paid attention to.
