Serine plays an important role in intermediary metabolism as a source of one carbon pool for nucleotide biosynthesis, as a precursor for glycine and glucose, and as a contributor to cysteine biosynthesis. A unique serine-glycine cycling between the liver and the placenta has been demonstrated in the sheep fetus. We hypothesized that, because of serine's role in growth and development, significa...

Objective: Whether orally administered L-serine influences amino acid metabolism in the brain was investigated. Methods: L-Serine (6 mmol/10 ml/kg) was orally administered to rats after a 9 hr fast and plasma and brain samples were obtained at 30, 60 and 120 min in Experiment 1. In Experiment 2, the effect of L-serine and glycine on brain amino acid metabolism was compared. Results: In Experime...

D-serine is an endogenous ligand for N-methyl-D-aspartate glutamate receptors. Accumulating evidence including genetic associations of D-serine metabolism with neurological or psychiatric diseases suggest that D-serine is crucial in human neurophysiology. However, distribution and regulation of D-serine in humans are not well understood. Here, we found that D-serine is heterogeneously distribut...

The rates of conversion of glycine into serine and serine into glycine have been determined by administration of isotopically labelled glycine and serine (Arnstein & Neuberger, 1953; Elwyn & Sprinson, 1954; Arnstein & Keglevi6, 1956; Arnstein & Stankovid, 1956). The present investigation, which is concerned with the net synthesis of glycine from serine, and of serine from glycine, was carried o...

d-Serine is an amino acid present in mammalian urine that is inhibitory to Escherichia coli strains lacking a functional dsdA gene. Counterintuitively, a dsdA strain of E. coli clinical isolate CFT073 hypercolonizes the bladder and kidneys of mice relative to wild type during a coinfection in the murine model of urinary tract infection. We are interested in the mechanisms for uptake of d-serine...

BACKGROUND D-serine is an endogenous co-agonist of the N-Methyl D-Aspartate Receptor (NMDAR) that plays a crucial role in cognition including learning processes and memory. Decreased D-serine levels have been associated with age-related decline in mechanisms of learning and memory in animal studies. Here, we asked whether D-serine administration in older adults improves cognition. RESULTS D-s...

Clinical trials demonstrated that D-serine administration improves schizophrenia symptoms, raising the possibility that altered levels of endogenous D-serine may contribute to the N-methyl D-aspartate receptor hypofunction thought to play a role in the disease. We hypothesized that cerebro-spinal fluid (CSF) D-serine levels are decreased in the patients due to reduced synthesis and/or increased...

d-Serine normally contributes up to 3% to total plasma serine and up to 23% in chronic renal failure. d-Serine is metabolized by tubular d-amino acid oxidase (D-AAO), and highd-serine plasma levels are nephrotoxic; both events are localized in the straight part of the proximal tubule. We therefore investigated if and howd-serine is reabsorbed there. We microinfused14C-labeledd- or -l-serine + [...