The effect of the oral administration of leucine on the metabolism of tryptophan

Amino Acids Composition of Liver, Heart and Kidneys of <i>Thryonomys swingerianus </i>(Temminck 1827) Compared

Amino acids composition of Thryonomysswingerianus is reported. Whereas protein values (g100g-1) were liver (74.1), kidney (91.5), heart (84.6); corresponding total amino acid values were 93.5, 83.2 and 80.6. True protein from the crude protein of the samples ran thus: liver>kidney>heart. Of the twenty parameters reported on, liver was best in 12/20 (60.0%), kidney and heart both shared the second position of 4/20(20%) each. Among the essential amino acids, leucine predominated in both liver (7.96g100g-1 protein) and kidney (8.11g100g-1 protein) but valine (6.21g100g-1 protein) predominated in the heart. The P-PER values were; P-PER1: 2.78 (liver), 2.91(kidney), 0.716 (heart) and P-PER2: 2.71 (liver), 2.90 (kidney), 0.564 (heart). However, there was a reverse between liver and kidney in the EAAI values with liver (92.0) > kidney (90.2) > heart (87.6) with corresponding BV values of 88.5 > 86.6 > 83.7. In the amino acids scoring pattern, Ser was limiting in liver (0.533) and heart (0.394) but Thr (0.490) in kidney in whole hen’s egg score comparison; in FAO/WHO scoring standards, Thr was limiting in liver (0.988) and kidney (0.625) but Leu (0.459) in heart. In pre-school requirements, liver recorded no limiting amino acid whereas Thr was limiting in kidney (0.735) and Leu was limiting in the heart (0.486). T.swingerianus red viscera was compared with the red viscera of livestock animals (cattle, sheep and pork) as well as FAO/WHO/UNU standards for total essential amino acids. Our results when compared with the livestock red viscera (without Trp) and FAO/WHO/UNU (g100g-1 protein), we have heart: grasscutter/cattle/sheep/pig:45.3 /46.0/42.7/46.6; kidney: grasscutter/cattle/sheep/pig: 47.6/43.8/42.5/46.7; liver: grasscutter/cattle/sheep/pig: 50.7/47.7/41.5/47.5 and grasscutter liver/kidney/heart/ FAO/WHO/UNU:50.7/47.6/45.3/32.8 showing that all the red viscera values in T.swingerianus were better than the essential amino acids in the FAO/WHO/UNU standards and livestock red viscera. Statistical values showed that significant differences existed among the samples at r=0.01.

Amino Acids Composition of Liver, Heart and Kidneys of <i>Thryonomys swingerianus </i>(Temminck 1827) Compared

Amino acids composition of Thryonomysswingerianus is reported. Whereas protein values (g100g-1) were liver (74.1), kidney (91.5), heart (84.6); corresponding total amino acid values were 93.5, 83.2 and 80.6. True protein from the crude protein of the samples ran thus: liver>kidney>heart. Of the twenty parameters reported on, liver was best in 12/20 (60.0%), kidney and heart both shared the second position of 4/20(20%) each. Among the essential amino acids, leucine predominated in both liver (7.96g100g-1 protein) and kidney (8.11g100g-1 protein) but valine (6.21g100g-1 protein) predominated in the heart. The P-PER values were; P-PER1: 2.78 (liver), 2.91(kidney), 0.716 (heart) and P-PER2: 2.71 (liver), 2.90 (kidney), 0.564 (heart). However, there was a reverse between liver and kidney in the EAAI values with liver (92.0) > kidney (90.2) > heart (87.6) with corresponding BV values of 88.5 > 86.6 > 83.7. In the amino acids scoring pattern, Ser was limiting in liver (0.533) and heart (0.394) but Thr (0.490) in kidney in whole hen’s egg score comparison; in FAO/WHO scoring standards, Thr was limiting in liver (0.988) and kidney (0.625) but Leu (0.459) in heart. In pre-school requirements, liver recorded no limiting amino acid whereas Thr was limiting in kidney (0.735) and Leu was limiting in the heart (0.486). T.swingerianus red viscera was compared with the red viscera of livestock animals (cattle, sheep and pork) as well as FAO/WHO/UNU standards for total essential amino acids. Our results when compared with the livestock red viscera (without Trp) and FAO/WHO/UNU (g100g-1 protein), we have heart: grasscutter/cattle/sheep/pig:45.3 /46.0/42.7/46.6; kidney: grasscutter/cattle/sheep/pig: 47.6/43.8/42.5/46.7; liver: grasscutter/cattle/sheep/pig: 50.7/47.7/41.5/47.5 and grasscutter liver/kidney/heart/ FAO/WHO/UNU:50.7/47.6/45.3/32.8 showing that all the red viscera values in T.swingerianus were better than the essential amino acids in the FAO/WHO/UNU standards and livestock red viscera. Statistical values showed that significant differences existed among the samples at r=0.01.

Simultaneous Identification and Evaluation of Amino Acid Profiles of the Male and Female Innards of <i>Neopetrolisthes maculatus</i>

This article reports the amino acid profiles of the innards of the male and female dry samples of N. maculatus collected from the Atlantic Ocean at Orimedu beach in Ibeju-Lekki, Lagos, Nigeria. The analytical results showed high values of amino acids being observed in both heterosexual samples (g 100g-1 protein): 8.17-8.32 (Leu), 8.35-10.3 (Asp), 17.6-18.2 (Glu) and 7.76-9.55 (Arg) with total amino acid values being greater in female innards (97.6g100g-1) than the male innards (95.5g 100g-1). These quality parameters were instructive of the quality of the amino acids in the innards of N. maculatus: P-PER1, (2.83-3.01), P-PER2 (2.89-2.96), EAAI (88.7-89.0), BV (85.0-85.5), Lys/Trp (L/T) (3.00-5.01), Met/Trp (M/T) (1.78-3.50) and Phe/Tyr (1.04-1.65). The pI values were close at 5.46-5.57. In the amino acid groups (classes), the following trend was observed: class I > IV >V > VI > II > III > VII. For the amino acid scores: serine (0.487-0.511) was limiting in both samples on the total hen’s egg scoring pattern; in provisional scoring pattern, Lys was limiting in both samples with values of 0.820-0.889 and in the pre-school amino acid requirements, Lys was also limiting at 0.778-0.843. In the statistical analyses total amino acid profiles as well as egg scores were significantly different between the two samples whereas quality scores in pre-school amino acid requirements and provisional amino acid scoring pattern were both not significantly different between the two samples all at r=0.01. Among the EAAs, six out of nine (66.7%) were more concentrated in the male innards and three of nine (33.3%) were more concentrated in the female. Thus the overall summary showed the male innards amino acids were of better quality than in the female as shown: male innards EEA = 46.1 g100g-1 and 46.0 g100g-1 in the female with corresponding TNEAA of 49.3g 100g-1 and 51.6g 100g-1 respectively.

Simultaneous Identification and Evaluation of Amino Acid Profiles of the Male and Female Innards of <i>Neopetrolisthes maculatus</i>

This article reports the amino acid profiles of the innards of the male and female dry samples ofN. maculatuscollected from the Atlantic Ocean at Orimedu beach in Ibeju-Lekki, Lagos, Nigeria. The analytical results showed high values of amino acids being observed in both heterosexual samples (g 100g-1protein): 8.17-8.32 (Leu), 8.35-10.3 (Asp), 17.6-18.2 (Glu) and 7.76-9.55 (Arg) with total amino acid values being greater in female innards (97.6g100g-1) than the male innards (95.5g 100g-1). These quality parameters were instructive of the quality of the amino acids in the innards ofN. maculatus: P-PER1, (2.83-3.01), P-PER2(2.89-2.96), EAAI (88.7-89.0), BV (85.0-85.5), Lys/Trp (L/T) (3.00-5.01), Met/Trp (M/T) (1.78-3.50) and Phe/Tyr (1.04-1.65). ThepIvalues were close at 5.46-5.57. In the amino acid groups (classes), the following trend was observed: class I > IV >V > VI > II > III > VII. For the amino acid scores: serine (0.487-0.511) was limiting in both samples on the total hen’s egg scoring pattern; in provisional scoring pattern, Lys was limiting in both samples with values of 0.820-0.889 and in the pre-school amino acid requirements, Lys was also limiting at 0.778-0.843. In the statistical analyses total amino acid profiles as well as egg scores were significantly different between the two samples whereas quality scores in pre-school amino acid requirements and provisional amino acid scoring pattern were both not significantly different between the two samples all at r=0.01. Among the EAAs, six out of nine (66.7%) were more concentrated in the male innards and three of nine (33.3%) were more concentrated in the female. Thus the overall summary showed the male innards amino acids were of better quality than in the female as shown: male innards EEA = 46.1 g100g-1and 46.0 g100g-1in the female with corresponding TNEAA of 49.3g 100g-1and 51.6g 100g-1respectively.

Amino Acid Profiles of the Flesh of the Heterosexual Pairs of <i>Neopetrolisthes maculatus</i>

This paper reports on amino acid profiles of the flesh of heterosexuals of porcellanids collected from the Atlantic Ocean at Orimedu beach in Ibeju-Lekki, Lagos, Nigeria. Results showed that high values of amino acids were observed in the heterosexual flesh of Neopetrolisthes maculatus (g 100g-1 protein): 17.7 – 17.8 (Glu), 9.90 – 10.0 (Asp), 8.70 – 9.07 (Arg), 7.23 – 7.94 (Leu) and 5.81 – 6.06 (Gly). Total essential amino acid values ranged from 45.2 – 46.2 g 100-1g. Predicted protein efficiency ratio was 3.82 – 4.14, the range of essential amino acid index was 86.9 – 89.9, the biological values ranged from 83.0 – 86.3. The Lys/Trp was 3.31-4.27. Serine was limiting amino acid (0.513 – 0.516) in the egg score comparison; under the essential amino acids scores, Lys (0.840) was limiting in female but Val (0.823) was limiting in the male; Lys (0.796 – 0.905) was limiting in both samples in the pre-school child amino acid requirements. It was observed that out of the twenty parameters determined, male flesh was more concentrated in 60% values than the female flesh and 40% better in female than male. Correlation coefficient result showed that significant differences existed in the amino acids composition at r = 0.01 of the N. maculatus samples.

Amino Acid Profiles of the Flesh of the Heterosexual Pairs of Neopetrolisthes maculatus

This paper reports on amino acid profiles of the flesh of heterosexuals of porcellanids collected from the Atlantic Ocean at Orimedu beach in Ibeju-Lekki, Lagos, Nigeria. Results showed that high values of amino acids were observed in the heterosexual flesh of Neopetrolisthes maculatus (g 100g-1 protein): 17.7 – 17.8 (Glu), 9.90 – 10.0 (Asp), 8.70 – 9.07 (Arg), 7.23 – 7.94 (Leu) and 5.81 – 6.06 (Gly). Total essential amino acid values ranged from 45.2 – 46.2 g 100-1g. Predicted protein efficiency ratio was 3.82 – 4.14, the range of essential amino acid index was 86.9 – 89.9, the biological values ranged from 83.0 – 86.3. The Lys/Trp was 3.31-4.27. Serine was limiting amino acid (0.513 – 0.516) in the egg score comparison; under the essential amino acids scores, Lys (0.840) was limiting in female but Val (0.823) was limiting in the male; Lys (0.796 – 0.905) was limiting in both samples in the pre-school child amino acid requirements. It was observed that out of the twenty parameters determined, male flesh was more concentrated in 60% values than the female flesh and 40% better in female than male. Correlation coefficient result showed that significant differences existed in the amino acids composition at r = 0.01 of the N. maculatus samples.

Effect of leucine on enzymes of the tryptophan-niacin metabolic pathway in rat liver and kidney

Dietary excess of leucine affects tryptophan-niacin metabolism adversely and has thus been implicated in the etiology of pellagra. To understand the biochemical basis of leucine-induced changes in tryptophan-niacin metabolism the effect of leucine on enzymes of tryptophan-niacin metabolism was investigated. Excess of leucine in the diet had no effect on rat liver 3-hydroxyanthranilate oxygenase and nicotinate phosphoribosyltransferase but significantly decreased the activity of quinolinate phosphoribosyltransferase of rat liver and kidney. The activities of tryptophan oxygenase in liver and picolinate carboxylase in kidney were significantly higher in leucine-fed animals than in the controls. Also, oxidation of [U-(14)C]tryptophan in vivo was higher in leucine-fed animals. Increased picolinate carboxylase and decreased quinolinate phosphoribosyltransferase activities would result in a decrease in NAD formation from dietary tryptophan. Lowered NAD formation from tryptophan particularly when the niacin concentrations in the diet are marginal would result in a state of conditioned niacin deficiency.

Amino acid composition of the whole body, flesh and exoskeleton of female common West African fresh water crab Sudananautes africanus africanus

The amino acid composition of the whole body (edible parts), flesh and exoskeleton of the female common West African fresh water crab Sudananautes africanus africanus was determined on a dry weight basis. The total essential amino acids ranged from 349.8 mg/g to 387.3 mg/g crude protein or from 48.5% to 49.8% of the total amino acid. Both the total amino acid and the total essential amino acid showed no significant differences among the samples at P<0.05. The amino acid score showed that lysine ranged from 0.9 to 1.2, making it a good food fortifier. The predicted protein efficiency ratio was 2.6-3.4, showing that the quality of protein was high. The carbohydrate content was high (57.5-59.1 g/100 g) but the protein was lower (15.7-18.6 g/100 g). The low level of the crude fibre in the flesh will make it good to serve as a food complement.

Nutritional deficiency and the skin

Cutaneous changes occur in deficiency states of many nutritional elements: ascorbic acid, retinol, protein-energy, cyanocobalamin, phytonadione (vitamin K), biotin, ribroflavin, pyridoxine, niacin, essential fatty acids, and zinc. There are also inherited disorders of copper, biotin, zinc, and tryptophan metabolism. Cutaneous vitamin D synthesis is inhibited by sunscreen use. The striking skin changes of the glucagonoma syndrome may be related to nutritional pathways.

Studies on metabolism of branched chain amino acids in brain and other tissues of rat with special reference to leucine

Leucine aminotransferase (EC 2.6.1.6) and 2-oxoisocaproate dehydrogenase (EC 1.2.4.3) were studied in rat cerebral cortex, cerebellum, brain stem, liver, and muscle in normal and animals starved for 48 hours. In the brain, leucine aminotransferase, valine aminotransferase, and 2-oxoisocaproate dehydrogenase showed a significant increase in starvation only in cerebellum while there was increase in 2-oxoisocaproate dehydrogenase in cerebral cortex only. A significantly high increase in the activity of 2-oxoisocaproate dehydrogenase was observed in muscle in starvation. A significant decrease in the activity of leucine aminotransferase was observed in liver in starvation. The increase in the activity of 2-oxoisocaproate dehydrogenase in muscle and a decrease in the activity of leucine aminotransferase in liver in starvation indicate that the leucine is predominantly metabolized in extra hepatic tissues particularly in muscle. As a result of intraperitoneal administration of 2 ml of leucine (5 mM), a significant increase in 2-oxoisocaproate dehydrogenase occurred in cerebral cortex, liver, and muscle while a profound increase in the activity of glutamate dehydrogenase (EC 1.4.1.2) was observed in all the brain regions and liver under these conditions. A significant increase in the content of glutamic acid, alanine, and GABA was observed in all the three regions of the brain after the administration of leucine. A significant increase in the content of glutamine was observed only in the cerebellum and cerebral cortex after leucine administration. These results indicate that leucine in brain might contribute to the formation of glutamate, not only by transamination, but also by promoting glutamate dehydrogenase activity. Thus, there is a change in the metabolism of glutamate family of amino acids and energy depletion. These results are discussed in relation to the brain function.

Interactions of thiamin, riboflavin, and other B-vitamins

Interactions of the B-complex vitamins are essential in the performance of metabolic and catabolic reactions in the body. Even vitamin C and the fat-soluble vitamins may be involved in these interactions. Clinical and biochemical aberrations associated with various disease states can often be explained on the basis of these vitamin interrelationships. Health and nutritional well-being are dependent upon the maintenance and proper functioning of these vitamin-dependent metabolic pathways.

Effect of leucine at different levels of pyridoxine on hepatic quinolinate phosphoribosyl transferase (EC 2.4.2.19) and leucine aminotransferase (EC 2.6.1.6) in rats

1. Effects of incorporating 30 g leucine/kg into diets on quinolinate phosphoribosyl transferase (QPRT; EC 2.4.2.19) activity and leucine aminotransferase (EC 2.6.1.6) activity were studied in groups of rats receiving 5, 30 and 60 micrograms of pyridoxine/10 g diet. 2. The results indicated that 30 g leucine/kg diet significantly reduced the QPRT activity when the diets provided 5 micrograms pyridoxine/10 g and that the effect was only marginal when the diet included 30 micrograms pyridoxine/10 g. The inhibitory effect was completely absent when the diet provided higher amounts of pyridoxine (60 microgram/10 g). 3. These results suggest that additional amounts of pyridoxine are necessary to counteract the effects of excess of leucine in the diet. 4. Leucine aminotransferase activity was increased in rats given diets containing higher amounts of pyridoxine; supplementary leucine also increased the enzyme activity.

Nicotinamide nucleotides in the erythrocytes of patients suffering from pellagra

1. The nicotinamide nucleotide concentrations in the erythrocytes of subjects suffering from pellagra (pellagrins) were not lower than those in normal subjects, but the ability of erythrocytes to synthesize these nucleotides in vitro was significantly lower in pellagrins. 2. The oral administration of 10g. of l-leucine daily for 5 days depressed the nicotinamide nucleotide-synthesizing ability of erythrocytes both in normal subjects and in pellagrins. This was not accompanied by changes in the nucleotide concentration in erythrocytes. 3. Quinolinic acid brought about a significant inhibition of the synthesis of nicotinamide nucleotides in vitro. Such inhibition was partially overcome by increasing the concentration of nicotinic acid in the medium.