LysE of Corynebacterium glutamicum belongs to a large new superfamily of translocators whose members are probably all involved in the export of small solutes. Here, the transcript initiation site of lysE, and its divergently transcribed regulator gene, lysG, are identified. Single-copy transcriptional fusions of lysE with lacZ, and titration experiments, show that LysG is the positive regulator...

The ornithine + citrulline -+ arginine cycle of urea synthesis originally proposed by Krebs and Henseleit (1) has had increasing experimental support (2-10). The position of citrulline in the cycle, however, has been questioned (11). With the advent of the successful separation of the two over-all enzymatic steps, ornithine -+ citrulline and citrulline -+ arginine (lo), from the intact cellular...

Increases in arginase activity have been reported in a variety of disease conditions characterized by vascular dysfunction. Arginase competes with NO synthase for their common substrate arginine, suggesting a cause and effect relationship. We tested this concept by experiments with streptozotocin diabetic rats and high glucose (HG)-treated bovine coronary endothelial cells (BCECs). Our studies ...

BACKGROUND Duchenne muscular dystrophy (DMD) is an X-linked recessive disease that affects 1 in 3500-6000 male births. Despite broad research aiming to improve muscle function as well as heart and brain function, sufficient therapeutic efficacy has not yet been achieved and current therapeutic management is still supportive. In a recent pilot trial, oral treatment with L-arginine and metformin ...

PURPOSE The blood-brain tumor barrier (BTB) significantly limits the delivery of chemotherapeutics to brain tumors. Nitric oxide (NO) is involved in the regulation of cerebral vascular permeability. We investigated the effects of NO donors, L-arginine and hydroxyurea, on BTB permeability in 9L gliosarcoma-bearing Fischer rats. EXPERIMENTAL DESIGN The rats implanted with 9L gliosarcoma were do...

The kidney is a major site of arginine synthesis where citrulline is converted to arginine via argininosuccinate synthase (ASS) and lyase (ASL). The rate-limiting step in arginine synthesis by the normal kidney is the rate of citrulline delivery and uptake to the renal cortex. We tested whether with chronic kidney disease (CKD) renal arginine synthesis may be compromised. Using the 5/6 renal ab...

We investigated nitric oxide (NO) production in Paramecium caudatum, and the role of NO production in population growth in culture and thermoregulation. Nitrite (NO2 -) concentration in media containing P. caudatum [6350 ± 390 (SD) paramecia/ml] was 2.37 ± 0.53 μM after 6 h, compared to 0.16 ± 0.06 μM in media alone (p<0.005), and the NO synthase (NOS) inhibitor, Nω-nitro-L-arginine methylester...

The diffusible messenger NO plays multiple roles in neuroprotection, neurodegeneration, and brain plasticity. Argininosuccinate synthase (AS) is a ubiquitous enzyme in mammals and the key enzyme of the NO-citrulline cycle, because it provides the substrate L-arginine for subsequent NO synthesis by inducible, endothelial, and neuronal NO synthase (NOS). Here, we provide evidence for the particip...

Hypocitrullinemia and hypoargininemia but hyperprolinemia are associated with elevated plasma concentration of lactate in infants. Because the small intestine may be a major organ for initiating proline catabolism via proline oxidase in the body and is the major source of circulating citrulline and arginine in neonates, we hypothesized that lactate is an inhibitor of intestinal synthesis of cit...