GAA Research Library

GAA-creatine in elderly

The objective of this pilot trial was to evaluate the effects of 8-week GAA-creatine supplementation versus placebo on skeletal muscle and brain creatine levels, cognitive function, functional outcomes, and safety biomarkers in men and women aged 65 years and older. Twenty-one healthy elderly individuals (age 69.6 ± 4.9 years, body mass index 27.6 ± 4.2 […]

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GAA in urea cycle disorders

The urea cycle generates arginine that is one of the major precursors for creatine biosynthesis. Here we evaluate levels of creatine and guanidinoacetate (the precursor in the synthesis of creatine) in plasma samples (ns = 207) of patients (np = 73) with different types of urea cycle disorders (ornithine transcarbamylase deficiency (ns = 22; np […]

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Single-cell distribution of GAA synthesis

The enzymes AGAT and GAMT function together to synthesize creatine from arginine, glycine, and S-Adenosyl methionine. Deficiency in either enzyme or the creatine transporter, CT1, results in a devastating neurological disorder, Cerebral Creatine Deficiency Syndrome (CCDS). To better understand the pathophysiology of CCDS, we mapped the distribution of GATM and GAMT at single cell resolution, […]

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Phenotyping GAA in nocturnal enuresis

Nocturnal enuresis (NE) is a common problem among 10% school-aged children. The etiologies underlying childhood NE is complex and not fully understood nowadays. Nevertheless, increasing evidence suggests a potential link between neurobehavioral disorders and enuresis in children. In this study, we aimed to explore novel metabolomic insights into the pathophysiology of NE and also, its […]

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Regulation with GAA on muscle development

Guanidinoacetic acid is the direct precursor of creatine and its phosphorylated derivative phosphocreatine in the body. It is a safe nutritional supplement that can be used to promote muscle growth and development. Improving the growth performance of livestock and poultry and meat quality is the eternal goal of the animal husbandry, and it is also […]

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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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Cerebral GAA in GAMT deficiency

Guanidinoacetate methyltransferase deficiency is one of three cerebral creatine deficiency syndromes due to pathogenic variants in the GAMT gene (19p13.3). GAMT-D is characterized by the accumulation of guanidinoacetic acid (GAA) and the depletion of Cr, which result in severe global developmental delay (and intellectual disability), movement disorder, and epilepsy. The GAMT knockout (KO) mouse model […]

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GAA in newborn screening for GAMT deficiency identification

GAMT deficiency is an inherited metabolic disorder that impairs the synthesis of creatine. Lack of brain creatine can cause intellectual disability, autistic-like behavior, seizures, and movement disorders. Identification at birth and immediate therapy can prevent intellectual disability and seizures. Here we report the first two cases of GAMT deficiency identified at birth by newborn screening […]

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Physiological roles of GAA and its relationship with arginine

The role of guanidinoacetic acid (GAA) and its relationship with arginine was reviewed in order to define a replacement ratio between GAA and arginine for broiler diet formulation, the ratio being of how much arginine could be spared, or replaced by GAA. Guanidionoacetic acid, the precursor of creatine, can be synthesized de novo from the […]

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GAA supplementation and nitrogen retention

Creatine stores high-energy phosphate bonds in muscle and is synthesized in the liver through methylation of guanidinoacetic acid (GAA). Supplementation of GAA may therefore increase methyl group requirements, and this may affect methyl group utilization. Our experiment evaluated the metabolic responses of growing cattle to postruminal supplementation of GAA, in a model where methionine (Met) […]

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