vitamin-b-12 and glycocyamine

The purpose of the study is to evaluate the effects of creatine supplementation on homocysteine (Hcy) plasma levels after acute exercise in humans.. Twenty-three young (under-20) soccer players were divided into 2 groups: creatine (Cr)- and placebo (Pla)-supplemented groups. The supplementation was performed in double-blind controlled manner using creatine or placebo tablets with 0.3 g/kg during 7 days. Before and after 7 days of supplementation, the athletes performed an acute high-intensity sprint exercise (two consecutive running-based anaerobic sprint test protocol consisted in 6 × 35 m sprint with 10 s between them). Blood samples were collected before and after 7 days of supplementation as well as 0 and 1 h after exercise protocol.. Homocysteine concentration significant increased (P < 0.05) 1 h after acute exercise (18%). Acute exercise also decreased red blood cell S-adenosylmethionine (SAM) 30% with no changes in SAM/SAH ratio. Seven days of creatine supplementation were able to increase (P < 0.05) plasma creatine concentration (Pla 130.1 ± 21.7 vs Cr 1,557.2 ± 220.3 μmol/L) as well as decrease (P < 0.05) plasma guanidinoacetic acid (33%). Controversially, creatine supplementation did not change Hcy plasma level after 7-day supplementation (Pla 6.9 ± 0.2 vs Cr 7.2 ± 0.2 μmol/L) or after acute exercise (Pla 8.2 ± 0.3 vs Cr 8.4 ± 0.3 μmol/L). No changes in plasma vitamin B12 and folate as well as cysteine and methionine were found.. Seven days of creatine supplementation does not avoid increased plasma Hcy induced by acute sprint exercise in humans.

Topics: Adolescent; Creatine; Cysteine; Dietary Supplements; Double-Blind Method; Energy Intake; Exercise; Feeding Behavior; Folic Acid; Glycine; Healthy Volunteers; Homocysteine; Humans; Male; Methionine; S-Adenosylmethionine; Soccer; Vitamin B 12

Methylation is an important aspect of many fundamental biological processes including creatine biosynthesis. We studied five patients with an inborn error of cobalamin metabolism to characterize the relation between homocysteine and creatine metabolism. Plasma guanidinoacetate concentrations were increased, 14.9 +/- 4.8 micromol/L (p < 0.0001), whereas plasma creatine concentrations were in the low reference range, 43.8 +/- 20.7 micromol/L (p = not significant). Individuals with combined methylmalonic aciduria and homocystinuria have a functional impairment of the creatine synthetic pathway probably secondary to a relative depletion of labile methyl groups. The neurotoxic effects of guanidinoacetate may be partly responsible for the observed neurological phenotype.

Topics: Adult; Amino Acid Metabolism, Inborn Errors; Child; Child, Preschool; Creatine; Female; Glycine; Homocysteine; Homocystinuria; Humans; Male; Methionine; Methylmalonic Acid; Vitamin B 12

Topics: Acetates; Choline; Folic Acid; Glycine; Guanidines; Lecithins; Lipid Metabolism; Liver; Phosphatidylcholines; Phosphatidylethanolamines; Phospholipids; Rats; Research; Vitamin B 12