Vitamin B-6 restriction tends to reduce the red blood cell glutathione synthesis rate without affecting red blood cell or plasma glutathione concentrations in healthy men and women.

Background: Glutathione plays various protective roles in the human body. Vitamin B-6 as pyridoxal-5'-phosphate (PLP) is required as the coenzyme in the formation of glutathione precursors. Despite this obligatory role of PLP, previous studies from this laboratory showed that vitamin B-6 deficiency caused elevated glutathione concentrations in rat liver and human plasma.

Production of 1-carbon units from glycine is extensive in healthy men and women.

Glycine undergoes decarboxylation in the glycine cleavage system (GCS) to yield CO(2), NH(3), and a 1-carbon unit. CO(2) also can be generated from the 2-carbon of glycine by 10-formyltetrahydrofolate-dehydrogenase and, after glycine-to-serine conversion by serine hydroxymethyltransferase, from the tricarboxylic acid cycle. To evaluate the relative fates of glycine carbons in CO(2) generation in healthy volunteers (3 male, 3 female, aged 21-26 y), primed, constant infusions were conducted using 9.

Moderate dietary vitamin B-6 restriction raises plasma glycine and cystathionine concentrations while minimally affecting the rates of glycine turnover and glycine cleavage in healthy men and women.

Glycine is a precursor of purines, protein, glutathione, and 1-carbon units as 5,10-methylenetetrahydrofolate. Glycine decarboxylation through the glycine cleavage system (GCS) and glycine-serine transformation by serine hydroxymethyltransferase (SHMT) require pyridoxal 5'-phosphate (PLP; active form of vitamin B-6) as a coenzyme. The intake of vitamin B-6 is frequently low in humans.

Evaluation of long-term treatment of children with congenital lactic acidosis with dichloroacetate.

Objective: The purpose of this research was to report results on long-term administration of dichloroacetate in 36 children with congenital lactic acidosis who participated previously in a controlled trial of this drug.

Patients And Methods: We conducted a randomized control trial, followed by an open-label study. Data were analyzed for each patient from the time they began treatment through May 2005.

Glycine turnover and decarboxylation rate quantified in healthy men and women using primed, constant infusions of [1,2-(13)C2]glycine and [(2)H3]leucine.

Glycine plays several roles in human metabolism, e.g. as a 1-carbon donor, in purine synthesis, and as a component of glutathione.