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GAA supplementation in cattle infographic

Guanidinoacetic acid (GAA) is a naturally occurring precursor to creatine, an source of energy for skeletal muscle. Feeding GAA to chickens, pigs and cattle improves growth performance through a mechanism that may include increased serum IGF-1 and feed conversion. The formation of creatine from GAA uses a considerable number of methyl donors, arginine and glycine […]

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GAA as model for small molecule biomarker

The accurate and efficient measurement of small molecule disease markers for clinical diagnosis is of great importance. In this study, a quadrupole-linear ion trap (Q-LIT) tandem mass spectrometer was designed and built in our laboratory. Target precursor ions were first selected in the quadrupole, and then injected, trapped, and fragmented simultaneously in the linear ion […]

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GAA neurotoxicity and protective role of creatine

Guanidinoacetate methyltransferase deficiency is an inborn error of metabolism that results in decreased creatine and increased guanidinoacetate (GAA) levels. Patients present neurological symptoms whose mechanisms are unclear. We investigated the effects of an intrastriatal administration of 10 μM of GAA (0.02 nmol/striatum) on energy metabolism, redox state, inflammation, glutamate homeostasis, and activities/immunocontents of acetylcholinesterase and […]

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Quantitative analysis of GAA and underivatized AAs

Quantitative amino acid analysis has diverse applications in clinical diagnostics, biomedical research, and agriculture. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) enables more rapid and specific detection of amino acids in comparison to traditional, gold-standard ninhydrin-based methods. However, triple quadrupole mass spectrometers are unable to definitively differentiate isomers and are susceptible to ion suppression, both of which […]

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HPLC-MS method for detecting endogenous GAA

A simple, rapid and sensitive HPLC-MS/MS method for simultaneous determination of 4 of amino acids, guanidinoacetic acid, S-adenosylmethionine and S-adenosylhomocysteine in human plasma was developed and validated. The method requires no tedious sample preparation, derivatization reagents or ion-pairing reagents. Samples were prepared by combining plasma with a chilled mixture of acetonitrile (ACN) and water, followed […]

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LC-MS/MS measurements of urinary GAA and creatine

Cerebral Creatine deficiency syndromes (CCDS) include three hereditary diseases affecting the metabolism of creatine (Cr): arginine glycine amidinotransferase deficiency, guanidinoacetate methyltransferase deficiency and disorders of creatine transporter. These pathologies cause a brain creatine deficiency responsible of non-specific neurological impairments with mental retardation. LC-MS/MS measurements of guanidinoacetic acid (GAA) and creatine in urine and plasma are […]

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GAA and creatine determination with LC-MS/MS

The biosynthesis of creatine (Cr) is closely related to the bioavailability of guanidinoacetate (GAA). The lack of one or the other may compromise their role in the energy transport and cell signaling. A reliable estimate of their levels in biological samples is imperative since they are important markers of many metabolic disorders. Therefore, a new […]

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Pb-induced nephrotoxicity elevates GAA in urine

Chronic kidney disease is a worldwide problem, and Pb contamination is a potential risk factor. Since current biomarkers are not sensitive for the diagnosis of Pb-induced nephrotoxicity, novel biomarkers are needed. Metformin has both hypoglycaemic effects and reno-protection ability. However, its mechanism of action is unknown. We aimed to discover the early biomarkers for the […]

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GAA promotes myoblast differentiation

Guanidinoacetic acid (GAA), an amino acid derivative that is endogenous to animal tissues including muscle and nerve, has been reported to enhance muscular performance. MicroRNA (miRNA) is a post-transcriptional regulator that plays a key role in nutrient-mediated myogenesis. However, the effects of GAA on myogenic differentiation and skeletal muscle growth, and the potential regulatory mechanisms […]

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Metformin affected GAA in Becker muscular dystrophy

The L-arginine/nitric oxide synthase (NOS) pathway is considered to be altered in muscular dystrophy such as Becker muscular dystrophy (BMD). We investigated two pharmacological options aimed to increase nitric oxide (NO) synthesis in 20 male BMD patients (age range 21-44 years): (1) supplementation with L-citrulline (3 × 5 g/d), the precursor of L-arginine which is […]

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