The creatine biosynthetic pathway is essential for cellular phosphate associated energy production and storage, particularly in tissues having higher metabolic demands. Guanidinoacetate N-Methyl transferase (GAMT) is an important enzyme in creatine endogenous biosynthetic pathway, with highest expression in liver and kidney. GAMT deficiency is an inherited autosomal recessive trait that was the...

The objective of the study was to develop a simple, specific and stability-indicating HPLC method for the simultaneous determination of creatine phosphate sodium (CPS) and its related substances in pharmaceutical formulation. Separation of creatine phosphate sodium from its major process impurities and degradation products was achieved on a Hypersil BDS C18 column (250 × 4.6 mm, 5 μm) with an a...

Since creatinine excretion reflects a continuous loss of creatine and creatine phosphate, there is a need for creatine replacement, from the diet and/or by de novo synthesis. Creatine synthesis requires three amino acids, methionine, glycine, and arginine, and two enzymes, l-arginine:glycine amidinotransferase (AGAT), which produces guanidinoacetate acid (GAA), and guanidinoacetate methyltransf...

Background A typical oral creatine supplementation regimen involving a 5-7 day “loading phase” of 20-25 grams/day followed by a “maintenance phase” of 5-7 grams/day is typically considered as necessary to adequately saturate skeletal muscle as a lesser dose of creatine is insufficient in doing so. This rationale also assumes that the majority, if not all, of the creatine ingested at this dosage...

The purpose of this investigation was to develop a simple colorimetric method for creatine kinase (CK). The new method is based on the reaction of creatine, formed enzymatically from creatine phosphate and ADP, with different glyoxal compounds. Hydrated glyoxals, such as para-nitrophenyl, 2-thiophene, 4- biphenyl, 4, 4' -biphenyl,α-naphthyl, β-naphthyl, para-chlorophenyl, and styryl were...

Concentrations of creatinine, as determined in serum by a method involving the combined use of creatinine amidohydrolase (EC 3.5.2.10) and alkaline sodium picrate were found to be factitiously low, owing to a reversal of the enzyme reaction. This effect could be eliminated by converting creatine, the product of the enzymic reaction, to creatine phosphate. The combined enzymic-Jaff#{233} method ...

Intracellular acidosis due mainly to lactic acid accumulation has been regarded as the most important cause of skeletal muscle fatigue. Recent studies on mammalian muscle, however, show little direct effect of acidosis on muscle function at physiological temperatures. Instead, inorganic phosphate, which increases during fatigue due to breakdown of creatine phosphate, appears to be a major cause...

Creatine transport has been assigned to creatine transporter 1 (CRT1), encoded by mental retardation associated SLC6A8. Here, we identified a second creatine transporter (CRT2) known as monocarboxylate transporter 12 (MCT12), encoded by the cataract and glucosuria associated gene SLC16A12. A non-synonymous alteration in MCT12 (p.G407S) found in a patient with age-related cataract (ARC) leads to...

OBJECTIVES Creatine plays a pivotal role in brain energy homeostasis, and altered cerebral energy metabolism may be involved in the pathophysiology of depression. Oral creatine supplementation may modify brain high-energy phosphate metabolism in depressed subjects. METHODS Eight unipolar and two bipolar patients with treatment-resistant depression were treated for four weeks with 3-5 g/day of...