A characteristic consequence of a biotin deficiency in animals is a decreased ability to fix C402 into various tissue components including the amino acid arginine (1). Carbon dioxide is incorporated into arginine as a result of the conversion of ornithine to citrulline in the Krebs-Henseleit urea cycle (2). The methods developed by Cohen and Hayano (3, 4) for the synthesis of citrulline from or...

Nitric oxide, which mediates influences of numerous neurotransmitters and modulators on vascular smooth muscle and leukocytes, can be formed in the brain from arginine by an enzymatic activity that stoichiometrically generates citrulline. We show that glutamate and related amino acids, such as N-methyl-D-aspartate, markedly stimulate arginine--citrulline transformation in cerebellar slices stoi...

Citrulline possesses a highly specific metabolism that bypasses splanchnic extraction because it is not used by the intestine or taken up by the liver. The administration of citrulline may be used to deliver available nitrogen for protein homeostasis in peripheral tissues and as an arginine precursor synthesized de novo in the kidneys and endothelial and immune cells. Fresh research has shown t...

1. The kinetics, specificity, pH-and Na +-dependency of L-citrulline transport were examined-2-in unstimulated and lipopolysaccharide (LPS) activated murine macrophage J774 cells. The dependency of nitric oxide production on extracellular arginine or citrulline was investigated in cells activated with LPS (1 μg ml-1) for 24 h. 2. In unstimulated J774 cells transport of citrulline was saturable ...

A characteristic consequence of a biotin deficiency in animals is a decreased ability to fix C402 into various tissue components including the amino acid arginine (1). Carbon dioxide is incorporated into arginine as a result of the conversion of ornithine to citrulline in the Krebs-Henseleit urea cycle (2). The methods developed by Cohen and Hayano (3, 4) for the synthesis of citrulline from or...

Background: The achievement of an effective compound for prevention/treatment of hypertension with fewer complications has been of interest in recent years. OBJECTIVES: This study aimed to examine the effects of L-citrulline pretreatment on the tension of isolated rat aortic tissues precontracted by different vasoconstrictors. METHODS: Sixteen male Wistar rats (300-350g) were randomly divided i...

Functional studies show that increased renal nitric oxide (NO) mediates the renal vasodilation and increased glomerular filtration rate that occur during normal pregnancy. We investigated whether changes in the constitutive NO synthases (NOS), endothelial (eNOS) and neuronal (nNOS), were associated with the increased renal NO production in normal midterm pregnancy in the rat. In kidneys from mi...

BACKGROUND The amino acid arginine plays a key role in many metabolic processes in health and disease. Low arginine concentrations are found in various illnesses in children. OBJECTIVE The objective was to investigate the relation between plasma concentrations of arginine (and precursor amino acids) and severity of inflammation in critically ill children. DESIGN This was an observational co...

Background One goal of supplementation has been to increase blood flow to skeletal muscle during exercise. Raw L-citrulline (RC) and raw L-arginine (RA) has often been used for its vasodilatory effects, and recently, citrulline and arginine have been bound to a whey peptide (CP and AP, respectively) to increase bioavailability. The purpose of the present study was to compare the acute hemodynam...