Mitochondrial adenine nucleotide translocation was measured in the presence of creatine or creatine phosphate to test the proposed functional couple between the nucleotide translocase and creatine kinase. Rat heart mitochondria were preloaded with the corresponding nucleotide which reacts with creatine kinase only after it is transported across the mitochondrial membrane; namely, radioactive AT...

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...

This study was designed to determine the effects of ascorbic acid (AA) supplementation on immune status following a single bout exercise. In crossover design, 20 healthy sedentary women performed 30 min moderate-intensity cycling with (1000AA) or without (0AA) ingesting 1000 mg AA daily for 1 week. Blood samples were taken immediately before, after and 24 h post-exercise oxidative stress marker...

An effective and reliable method for the quantitative estimation of creatine kinase-MB, creatine kinase-MM variants and mitochondrial forms of creatine kinase in serum is presented. The high resolving power of isoelectric focusing allows the use of tetrazolium salts and meldola blue for the quantitative measurement without interfering non-specific reduction. The addition of thiol compounds to t...

Creatine is a nitrogen containing compound that serves as an energy shuttle between the mitochondrial sites of ATP production and the cytosol where ATP is utilized. There are two known disorders of creatine synthesis (both transmitted as autosomal recessive traits: arginine: glycine amidinotransferase (AGAT) deficiency; OMIM 602360; and guanidinoacetate methyltransferase (GAMT) deficiency (OMIM...

Total creatine (Cr(total) = phosphocreatine + creatine) concentrations differ substantially among mammalian skeletal muscle. Because the primary means to add Cr(total) to muscle is uptake of creatine through the sodium-dependent creatine transporter (CrT), differences in creatine uptake and CrT expression could account for the variations in [Cr(total)] among muscle fiber types. To test this hyp...

Recent reports highlight the utility of in vivo magnetic resonance spectroscopy (MRS) techniques to recognize creatine deficiency syndromes affecting the central nervous system (CNS). Reported cases demonstrate partial reversibility of neurologic symptoms upon restoration of CNS creatine levels with the administration of oral creatine. We describe a patient with a brain creatine deficiency synd...

To investigate the immediate and 12-months effects of a school-based intervention aiming to reduce risk enhance protective factors for eating disorder development in high school boys girls. In total, 4,149 adolescents from 30 schools were eligible inclusion 2,446 consented participate randomly allocated Healthy Body Image (HBI) or control group (classes as usual). The HBI is multicomponent cons...