Biochemical investigations, including urine organic acids, plasma and cerebrospinal fluid amino acid profiling, cerebrospinal fluid neurotransmitters, plasma and urine creatine, and guanidinoacetate
, were all unrevealing.
 The first two errors appear in creatine biosynthesis as autosomal recessive deficiencies of arginine-glycine amidinotransferase (AGAT) and guanidinoacetate
Stead L, Au K, Jacobs R, Brosnan M, Brosnan J (2001) Methylation demand and homocysteine metabolism: effects of dietary provision of creatine and guanidinoacetate
LPIN1 (lipin 1) and GAMT (guanidinoacetate
N-methyltransferase) expression levels are subjected to p53-dependent increase [144, 145].
Dietary creatine intake lowers creatine biosynthesis in rodents by inhibiting synthesis of guanidinoacetate
(GAA), the precursor of creatine, thereby sparing methyl groups and lowering total homocysteine (tHcys) (Guthmiller et al.
It is well known that the transfer of the amidino group of arginine to glycine to yield L-ornithine and guanidinoacetate
(GM), which is catalyzed by L-arginine:glycine amidinotransferase, represents the first of two steps in the biosynthesis of Cr.
And it is well known that creatine, as byproduct of choline metabolism, is formed when guanidinoacetate
(GAA) receives the SAM methyl under the action of guanidinoacetate
synthesis: production of guanidinoacetate
by the rat and human kidney in
methyltransferase activity in growing male rats fed on a raw field bean (Vicia faba L.) diet.
Inicialmente, arginina e glicina combinam para formar guanidinoacetate
e, em seguida, um grupo de S-metil adenosilmetionina e acrescentado para a formacao de creatina.
Creatine is synthesized when the amino acid S-adenosylmethionine (SAM) methylates guanidinoacetate
to form creatine and S-adenosylhomocysteine.