A possible physiological role of taurine in the adult female rat liver.

In agreement with previous results (Awapara, 1956), we noted that the taurine level in the liver of the adult female rat is higher than in the adult male rat: 9.44 and 2.08, respectively, expressed as a concentration (mumoles/g of liver).

Synthesis of taurine in rat liver and brain in vivo.

The in vivo formation of taurine and the analysis of labeled taurine precursors was examined in rat brain and liver at different times after an intracisternal injection of [35S]cysteine and an intraperitoneal injection of [3H]cysteine, simultaneously administered. The distribution pattern of radioactivity was similar in liver and brain. Most of the labeling in both organs (85% in brain and 80% in liver) was recovered in glutathione (oxidized and reduced), cysteic acid, cysteine sulfinic acid, hypotaurine, cystathionine, and a mixed disulfide of cysteine and glutathione.

Effect of dietary cholic acid and cholesterol on liver and kidney cystathionase and cysteine sulfinate decarboxylase activities and taurine concentrations in the rat.

Hepatic cystathionase and cysteine sulfinate decarboxylase activities are drastically affected by cholic acid added to the diet without cholesterol. When cholic acid and cholesterol are given together, only cysteine sulfinate decarboxylase activity is changed. Neither kidney enzyme activity nor taurine concentrations in the liver and kidney are noticeably modified, whatever the diet.

Dietary casein levels and taurine supplementation. Effects on cysteine dioxygenase and cysteine sulfinate decarboxylase activities and tuarine concentration in brain, liver and kidney of the rat.

Activities of cysteine dioxygenase (CO) and cysteine sulfinate decarboxylase (CSD) and the concentrations of taurine (T) in brain, liver and kidney of rats fed on diets containing 18% casein (A), 60% casein (B) and 17% casein supplemented with 1% of taurine (+T), were measured. Regardless of the diet, the three measurements were the same in the brains of the animals in the three groups. In the liver and the kidney, CO activity was also the same in all three diets, but a decrease of CSD activity associated to an increase of T was observed in rats fed on diet B.

Cysteine oxidase and cysteine sulfinic acid decarboxylase in developing rat liver.

The patterns of development of cysteine oxidase (CO) and cysteine sulfinic acid decarboxylase (CSD) in rat liver are not similar. It was observed that CO is not under sex control as CSD is. The results obtained agree with the idea that, in liver, as well as in brain, CSD is the limiting factor for the regulation of taurine biosynthesis.

Cystathionine in rat brain: catabolism in vivo.

The content of cystathionine was measured in 35 rat brains; the range was 10-120 nmol/g wet weight and thus the variability of cystathionine content in rat brain was emphasized. The regional distribution of cystathionine was also determined: the highest level was found in cerebellum; the lowest level was observed in the white and gray matter of the hemispheres. These results are different from those obtained in other species.

Regional and subcellular distribution of taurine-synthesizing enzymes in the rat central nervous system.

The distribution of cysteine oxidase (CO) and cysteine sulfinate decarboxylase (CSD) was examined in 12 regions of the rat central nervous system (CNS). The distribution of CO activity, expressed as μmol of cysteine sulfinate formed per h per g, was the following: hypothalamus, superior and inferior colliculi, 94-99 μmol/h/g; olfactory bulbs, cerebral cortex, striatum, and hippocampus, 44-51 μmol/h/g; cerebellum, 71 μmol/h/g; pons-medula and spinal cord, 94 and 60 μmol/h/g, respectively. The distribution of CSD activity expressed as μmol of cysteine sulfinate decarboxylated per h per g was the following: hypothalamus and colliculi, 14-21 μmol/h/g; olfactory bulbs, cerebral cortex, striatum, hippocampus, and cerebellum, 8-13 μmol/h/g; pons-medulla, 7.

Free amino acids and related substances in human glial tumours and in fetal brain: comparison with normal adult brain.

An ion exchange automatic chromatographic analysis of the free amino acid concentrations of 18 human glial tumours and of 4 human fetal brains was carried out and the concentrations were compared to those of 13 biopsy specimens of normal adult brain. In addition, the concentrations of the amino acids of the glial tumours were compared to those of 7 intracerebral metastases of various origin. The chromatograms of several tumour specimens showed an unidentified peak overlapping proline.

New insights into the active center of rat liver cystathionase.

Treatment by urea of purified rat liver cystathionase (L-Cystathionine cysteine-lyase (deaminating), EC 4.4.1.

Rat liver cysteine sulfinate decarboxylase: purification, new appraisal of the molecular weight and determination of catalytic properties.

Rat liver cystein sulfinate decarboxylase (L-cystein sulfinate carboxylase) was purified approximately 500-fold. By cellulose acetate and polyacrylamide gel electrophoresis or by analytical ultracentrifugation, the purified enzyme appears to be nearly homogeneous. The Stokes radius (3.