Optimal conditions for ornithine carbamyl transferase determination. A simple micromethod without deproteinization

Ceriotti, G

doi:10.1016/0009-8981(73)90065-x

Cited by 67 publications

(23 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Liver of these spfy animals were removed at the time of sacrifice and stored at -80" C for later determination of ornithine transcarbamylase activity. Ornithine transcarbamylase activity, measured by the method of Ceriotti (13), ranged from 3.6-8.8 pmol citrulline formed/h/mg protein in spfy compared to our previously reported activity of 88-1 12 in CD-I mice (14). All animals studied were adults; however, the spfy males were older (aged 2-6 months) than the control CD-1 mice (Charles River; 2 months old).…”

Section: Methodsmentioning

confidence: 69%

Effect of Sodium Benzoate and Sodium Phenylacetate on Brain Serotonin Turnover in the Ornithine Transcarbamylase-Deficient Sparse-Fur Mouse

et al. 1988

View full text Add to dashboard Cite

Herein we examine the effects of sodium benzoate and sodium phenylacetate on feeding and central serotonin turnover in a child with citrullinemia and in an animal model of congenital hyperammonemia, the ornithine transcarbamylase-deficient sparse-fur (spfly) mouse. In the child, when the benzoate/phenylacetate dosage was increased from 200 to 375 mg/kg/day each, feeding decreased. There was an accumulation of benzoate and phenylacetate in blood and cerebrospinal fluid a s well a s an increased concentration of 5-hydroxyindoleacetic acid, a neurochemical marker for serotonin turnover, in cerebrospinal fluid. In the mouse, sodium benzoate had a biphasic effect on both plasma ammonium levels and brain serotonin turnover. Two percent oral benzoate was associated with an increase in ammonium level, while a 3% dose led to a decrease in ammonium. There was a similar effect on serotonin turnover noted in both the hyperammonemic spfly and control CD-lly mice. Sodium phenylacetate did not have a consistent effect on serotonin turnover. The mechanism by which benzoate increases brain serotonin turnover appears to involve competition with tryptophan for albumin binding sites. This results in increased free tryptophan in serum and brain. W e speculate that some of the clinical symptoms of benzoate intoxication may be a consequence of altered serotonin turnover in the brain. We suggest that drug levels be monitored during therapy. 36excretion in children with inborn errors of urea synthesis (1). This has resulted in prolonged survival. However, both intravenous drugs used to treat acute hyperammonemia and inadvertent oral overdoses have been associated with clinical toxicity including anorexia, irritability, lethargy, and coma (1, 2). Symptoms of intoxication in part simulate those of hyperammonemia. The mechanism of these behavioral alterations is unclear. Bachmann et al. (3) re~orted increased brain uvtake of Tm. the precursor of serotbnin,tn rats injected with 1 mmol/kg of sddium benzoate. Increased brain uvtake of T m and increased brain serotonin turnover have also been reported in experimentally induced and naturally occurring hyperammonemia (4-7). These findings, together with data showing an association of anorexia with increased serotonin turnover in children with urea cycle disorders (8), suggest that benzoate intoxication may involve altered serotonin turnover.In studying the effect of benzoate and phenylacetate on serotonin turnover, we initially present a case report of a child with citrullinemia who developed toxic symptoms during high dose therapy and was found to have increased levels of the metabolite of serotonin, HIAA, in cerebrospinal fluid. We then examine in more detail the interaction of hyperammonemia and benzoate/ phenylacetate treatment on brain serotonin turnover in the chronically hyperammonemic ornithine transcarbamylase deficient sparse-fur (spf/y) mouse. METHODSBiochemical methods. Plasma ammonium was measured by a microfluorometric adaptation of a glutamate dehydrogenase method as previously d...

show abstract

Section: Methodsmentioning

confidence: 69%

Effect of Sodium Benzoate and Sodium Phenylacetate on Brain Serotonin Turnover in the Ornithine Transcarbamylase-Deficient Sparse-Fur Mouse

et al. 1988

View full text Add to dashboard Cite

show abstract

“…The following examinations were carried out in duplicate on all the subjects: aspartate aminotransferase (18), alanine aminotransferase (18), -glutamyl transpeptidase (19), ornithine carbamyl transferase (20) and glutamic dehydrogenase (21). Enzyme activity concentrations are expressed in terms of U/1 serum (l Unit = l Substrate converted per minute under optimal conditions) measured at 37 °C.…”

Section: Methodsmentioning

confidence: 99%

“…The ornithine cärbamyl transferase activity was determined by a manual procedure (20), using a LKB 7400 Calculating Absorptiorheter (LKB Produckter AB, Bromma, Sweden). Since values for the serum enzymes were not normally distributed, the statistical analyses were performed with non-parametric statistical tests coxon rank-sum test) (22).…”

Section: Methodsmentioning

confidence: 99%

Clinical and Diagnostic Significance of Aspartate Aminotransferase Isoenzymes in Sera of Patients with Liver Diseases

Panteghini¹,

Malchiodi²,

Calarco³

et al. 1984

Clinical Chemistry and Laboratory Medicine

View full text Add to dashboard Cite

Summary: Serum aspartate aminotransferase isoenzymes were measured in 123 hospital patients with various liver diseases, using a new and simple immunochemical method.Our findings show the usefulness of this determination in estimating the severity of hepatic damage, especially if accompanied by the measurement of other mitochondrial enzymes/During hepatic damage, the cytoplasmic isoenzyme is found in greater quantities than the mitochondrial isoenzyme, but the level of the latter increases to a greater extent in acute liver diseases. Moreover, the values of mitochondrial aspartate aminotransferase activity and the ratio of mitochondrial to total aspartate aminotransferase in alcoholic hepatitis are higher than expected if so-called hepatic enzymes commonly measured in serum are considered. These results indicate that there is significant mitochondrial damage in alcoholic hepatitis. Klinische und diagnostische Bedeutung von

show abstract

“…Citrulline contained in the supernatant was separated on a 1 x 5 cm column prepared from Dowex-50 WX8 cation exchange resin (400-800 mesh) [5]. Citrulline content of eluted fractions was assayed by the method of Archibald [6] as modified by Ceriotti [7].…”

Section: ~~ _ _~mentioning

confidence: 99%

Urea as a Selective Inhibitor of Argininosuccinate Lyase

Menyhárt

Gróf

1977

Eur J Biochem

View full text Add to dashboard Cite

show abstract

Optimal conditions for ornithine carbamyl transferase determination. A simple micromethod without deproteinization

Cited by 67 publications

References 13 publications

Effect of Sodium Benzoate and Sodium Phenylacetate on Brain Serotonin Turnover in the Ornithine Transcarbamylase-Deficient Sparse-Fur Mouse

Effect of Sodium Benzoate and Sodium Phenylacetate on Brain Serotonin Turnover in the Ornithine Transcarbamylase-Deficient Sparse-Fur Mouse

Clinical and Diagnostic Significance of Aspartate Aminotransferase Isoenzymes in Sera of Patients with Liver Diseases

Urea as a Selective Inhibitor of Argininosuccinate Lyase

Contact Info

Product

Resources

About