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Biomedical subjects

S Segal

Publications and source records attributed to S Segal.

At least 703 records · Page 39Linked to original sources
PubMed1967

Lysine transport in human kidney: evidence for two systems.

Experiments with slices of human kidney cortex from two control subjects demonstrated two distinct transport systems for lysine (alpha and beta) which differ greatly in affinity and capacity. Both systems were found in kidney from two patients with cystinuria. Studies with rat kidney confirmed these findings. These experiments defined only a single transport system for cystine in kidney from both control and cystinuric subjects.

Adult↗
PubMed1967

The intracellular ratio of cysteine and cystine in various tissues.

1. The cysteine-cystine ratio was measured in rat kidney cortex, diaphragm, jejunum, liver and brain. 2. This ratio was determined by incubating these tissues in buffer containing [(35)S]cystine and then homogenizing the tissue in a buffered solution of N-ethylmaleimide. The products of this reaction were separated by high-voltage electrophoresis and the radioactivity in the cystine and 2-(l-2'-amino-2'-carboxyethylthio)-N-ethylsuccinimide regions was determined. 3. In these tissues cyst(e)ine was mainly present in the reduced form. 4. After incubation of [(35)S]cystine with rat jejunal segments it was found that 36% of the cystine in the medium has been reduced. 5. Anaerobiosis, Na(+)-free media, glucose and high concentrations of cystine and lysine were found not to affect significantly the cysteine-cystine ratio in rat kidney-cortex slices.

Animals↗
PubMed1967

Intestinal transport of cystine and cysteine in man: evidence for separate mechanisms.

Cystine and cysteine are transported by energy-dependent, mediated processes in human gut. When either of these amino acids is transported, only cysteine is recovered intracellularly, indicating that cystine is reduced to cysteine after achieving an intracellular location. In contrast to results with cystine, cysteine uptake is not defective in gut from cystinuric patients, nor do lysine and arginine compete with cysteine for transport. It is, therefore, concluded that cystine and cysteine are transported by different mechanisms, and that only the cystine transport mechanism is defective in cystinuria.

Arginine↗
PubMed1966

Electrophoretic heterogeneity of mammalian galactose dehydrogenase.

Electrophoretically distinct forms of galactose dehydrogenase were demonstrated in various tissues of the rat. Phylogenetic comparisons revealed considerable variation with species in mammalian liver zymograms; virtually no activity was demonstrable in fish, pigeon, and frog liver. Ontogenetic studies of the rat revealed sequential appearance of liver isoenzymes.

Alcohol Oxidoreductases↗