Protein Intake and Plasma Amino-acids of Infants of Low Birth Weight

Valman, H B; Brown, R. J. K.; Palmer, Trevor; Oberholzer, V. G.; Levin, B.

doi:10.1136/bmj.4.5790.789

Cited by 23 publications

(6 citation statements)

References 29 publications

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“…Expression of carnosinase-2 in tissues other than the liver, brain, and kidneys is limited shortly after birth and gradually increases to adult levels during adolescence. Accordingly, the plasma concentrations of carnosine are 5-10 µM in preterm infants, 3-5 µM in term infants, and absent in healthy adults (Asatoor et al 1970;Valman et al 1971). In humans, carnosinase-1 that is present in serum at a very high activity is synthesized and secreted mainly by the liver.…”

Section: Metabolism Of Carnosine In Humansmentioning

confidence: 99%

Important roles of dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline in human nutrition and health

2020

Amino Acids

331

192

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Taurine (a sulfur-containing β-amino acid), creatine (a metabolite of arginine, glycine and methionine), carnosine (a dipeptide; β-alanyl-l-histidine), and 4-hydroxyproline (an imino acid; also often referred to as an amino acid) were discovered in cattle, and the discovery of anserine (a methylated product of carnosine; β-alanyl-1-methyl-l-histidine) also originated with cattle. These five nutrients are highly abundant in beef, and have important physiological roles in anti-oxidative and antiinflammatory reactions, as well as neurological, muscular, retinal, immunological and cardiovascular function. Of particular note, taurine, carnosine, anserine, and creatine are absent from plants, and hydroxyproline is negligible in many plant-source foods. Consumption of 30 g dry beef can fully meet daily physiological needs of the healthy 70-kg adult human for taurine and carnosine, and can also provide large amounts of creatine, anserine and 4-hydroxyproline to improve human nutrition and health, including metabolic, retinal, immunological, muscular, cartilage, neurological, and cardiovascular health. The present review provides the public with the much-needed knowledge of nutritionally and physiologically significant amino acids, dipeptides and creatine in animal-source foods (including beef). Dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline are beneficial for preventing and treating obesity, cardiovascular dysfunction, and ageing-related disorders, as well as inhibiting tumorigenesis, improving skin and bone health, ameliorating neurological abnormalities, and promoting well being in infants, children and adults. Furthermore, these nutrients may promote the immunological defense of humans against infections by bacteria, fungi, parasites, and viruses (including coronavirus) through enhancing the metabolism and functions of monocytes, macrophages, and other cells of the immune system. Red meat (including beef) is a functional food for optimizing human growth, development and health.

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Section: Metabolism Of Carnosine In Humansmentioning

confidence: 99%

Important roles of dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline in human nutrition and health

2020

Amino Acids

331

192

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“…For example, Snyderman et al [1968] reported that milk protein intakes of 9 g/kg/day led to methionine elevations of 2–35 times normal; and Levy et al [1969] found that protein intakes of 7 g/kg/day led to plasma methionines of 315–1,206 µM. Very low‐birth‐weight babies even on normal diets may have plasma methionines over 67 µM [Zytkovicz et al, 2001], and such babies [Valman et al, 1971; Gaull et al, 1977; Ten Hoedt et al, 2007], or some with presently undefined abnormalities [Mudd et al, 2003], when taking in higher amounts of protein or methionine are especially likely to become hypermethioninemic.…”

Section: Additional Situations In Which Hypermethioninemia Has Been Rmentioning

confidence: 99%

Hypermethioninemias of genetic and non‐genetic origin: A review

Mudd

2011

American J of Med Genetics Pt C

163

166

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This review covers briefly the major conditions, genetic and non-genetic, sometimes leading to abnormally elevated methionine, with emphasis on recent developments. A major aim is to assist in the differential diagnosis of hypermethioninemia. The genetic conditions are: (1) Homocystinuria due to cystathionine β-synthase (CBS) deficiency. At least 150 different mutations in the CBS gene have been identified since this deficiency was established in 1964. Hypermethioninemia is due chiefly to remethylation of the accumulated homocysteine. (2) Deficient activity of methionine adenosyltransferases I and III (MAT I/III), the isoenzymes the catalytic subunit of which are encoded by MAT1A. Methionine accumulates because its conversion to S-adenosylmethionine (AdoMet) is impaired. (3) Glycine N-methyltrasferase (GNMT) deficiency. Disruption of a quantitatively major pathway for AdoMet disposal leads to AdoMet accumulation with secondary down-regulation of methionine flux into AdoMet. (4) S-adenosylhomocysteine (AdoHcy) hydrolase (AHCY) deficiency. Not being catabolized normally, AdoHcy accumulates and inhibits many AdoMet-dependent methyltransferases, producing accumulation of AdoMet and, thereby, hypermethioninemia. (5) Citrin deficiency, found chiefly in Asian countries. Lack of this mitochondrial aspartate-glutamate transporter may produce (usually transient) hypermethioninemia, the immediate cause of which remains uncertain. (6) Fumarylacetoacetate hydrolase (FAH) deficiency (tyrosinemia type I) may lead to hypermethioninemia secondary either to liver damage and/or to accumulation of fumarylacetoacetate, an inhibitor of the high K(m) MAT. Additional possible genetic causes of hypermethioninemia accompanied by elevations of plasma AdoMet include mitochondrial disorders (the specificity and frequency of which remain to be elucidated). Non-genetic conditions include: (a) Liver disease, which may cause hypermethioninemia, mild, or severe. (b) Low-birth-weight and/or prematurity which may cause transient hypermethioninemia. (c) Ingestion of relatively large amounts of methionine which, even in full-term, normal-birth-weight babies may cause hypermethioninemia.

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“…Carnosine is present in the plasma of human pre-term infants (mean ± s.d. 8.8 ± 7.1 µmol/l), but occurs at a lower concentration of 3.1 ± 7.5 µmol/l in older fullterm infants (Valman et al 1971) and is absent from normal adults (Perry et al 1967;Dunnett and Harris 1992). This agerelated disappearance of carnosine is correlated with an increase in serum carnosinase activity (EC 3.4.13.4).…”

Section: Introductionmentioning

confidence: 99%

Plasma carnosine concentration: diurnal variation and effects of age, exercise and muscle damage

Dunnett

Harris

Dunnett³

et al. 2002

Equine Veterinary Journal

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This study was undertaken as part of a larger investigation into carnosine metabolism and function in the Thoroughbred horse. More specifically, we wished to evaluate plasma carnosine concentration as a potential indicator of muscle carnosine status. In contrast to man, carnosine is present in equine plasma where its presence is consistent with the absence of plasma carnosinase. A significant effect of age on plasma carnosine concentration in resting Thoroughbred horses was observed. Values in horses age 3 years and older were 113-14.1 micromol/l, whereas concentrations in foals and yearlings were 3.9-8.7 micromol/l (P<0.001). Lower values in young horses may reflect lower skeletal muscle carnosine concentrations. There was no significant within-day variation in plasma carnosine concentration in fed and fasted horses (P>0.05). Intense exercise resulted in a small significant increase (P<0.05) in plasma carnosine concentration (pre-exercise, 10.3 +/- 1.0 micromol/l; postexercise, 12.4 +/- 4.4 micromol/l). Greater increases were observed (57.6-702.3 micromol/l) following onset of exercise-induced rhadomyolysis (ERS). An apparent relationship was observed between elevated plasma carnosine and increased plasma creatine kinase (CK) and aspartate transaminase (AST) activities. Plasma carnosine concentrations did not reflect the severity of the condition as determined by clinical examination. In conclusion, elevated plasma carnosine levels are observed following exercise induced muscle damage, with the greatest elevations occurring during episodes of external rhabdomylosis syndrome. Plasma carnosine measurements could provide an alternative clinical indicator of muscle damage; and in conjunction with plasma taurine measurements may be indicative of selective type 1 or type 2 muscle fibre damage. However, given the complexity of the analytical technique, its applications would probably be confined to specialist referral or research centres.

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Protein Intake and Plasma Amino-acids of Infants of Low Birth Weight

Cited by 23 publications

References 29 publications

Important roles of dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline in human nutrition and health

Important roles of dietary taurine, creatine, carnosine, anserine and 4-hydroxyproline in human nutrition and health

Hypermethioninemias of genetic and non‐genetic origin: A review

Plasma carnosine concentration: diurnal variation and effects of age, exercise and muscle damage

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