Intestinal Transport of Cystine and Cysteine in Man: Evidence for Separate Mechanisms*

Rosenberg, León E.; Crawhall, J. C.; Segal, Stanton

doi:10.1172/jci105508

Cited by 55 publications

(27 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To overcome the diarrhea and the poor intestinal absorption of cystine encountered in Case 1, L-cysteine hydrochloride was substituted for cystine. (Cysteine was reported to be absorbed much more efficiently than cystine [22].) Seventy nag/kg of body weight of cysteine and of homoserine was given to Case 2 at 9 a.m., at 12 noon and at 4 p.m. No diarrhea was observed during the next 24 hours or subsequently.…”

Section: Loading Experimentsmentioning

confidence: 99%

The Biosynthesis of Cystathionine in Patients with Homocystinuria

1968

View full text Add to dashboard Cite

Section: Loading Experimentsmentioning

confidence: 99%

The Biosynthesis of Cystathionine in Patients with Homocystinuria

1968

View full text Add to dashboard Cite

“…Type I heterozygotes show a normal amino acid urinary pattern, whereas type II and III are characterized by an increase of cystine, lysine, ornithine, and arginine urinary excretion. Type II has been described as having a more severe impairment of intestinal transport than type III, as demonstrated by a lack of increase in plasma level after an oral load of cystine or lysine (2,3). Subtype non-I grouped previous subtypes II and III (4).…”

mentioning

confidence: 99%

Comparison between SLC3A1 and SLC7A9 Cystinuria Patients and Carriers

Strologo¹,

Pras

Pontesilli³

et al. 2002

Journal of the American Society of Nephrology

234

193

View full text Add to dashboard Cite

Abstract. Recent developments in the genetics and physiology of cystinuria do not support the traditional classification, which is based on the excretion of cystine and dibasic amino acids in obligate heterozygotes. Mutations of only two genes (SLC3A1 and SLC7A9), identified by the International Cystinuria Consortium (ICC), have been found to be responsible for all three types of the disease. The ICC set up a multinational database and collected genetic and clinical data from 224 patients affected by cystinuria, 125 with full genotype definition. Amino acid urinary excretion patterns of 189 heterozygotes with genetic definition and of 83 healthy controls were also included. All SLC3A1 carriers and 14% of SLC7A9 carriers showed a normal amino acid urinary pattern (i.e., type I phenotype). The rest of the SLC7A9 carriers showed phenotype non-I (type III, 80.5%; type II, 5.5%). This makes the traditional classification imprecise. A new classification is needed: type A, due to two mutations of SLC3A1 (rBAT) on chromosome 2 (45.2% in our database); type B, due to two mutations of SLC7A9 on chromosome 19 (53.2% in this series); and a possible third type, AB (1.6%), with one mutation on each of the above-mentioned genes. Clinical data show that cystinuria is more severe in males than in females. The two types of cystinuria (A and B) had a similar outcome in this retrospective study, but the effect of the treatment could not be analyzed. Stone events do not correlate with amino acid urinary excretion. Renal function was clearly impaired in 17% of the patients.

show abstract

“…Regardless of the cause of the decrease in specific activity, the experimental results mean that the true distribution ratio of cysteine is greater than the value simply determined by the ratio of intracellular to extracellular radioactivity in cysteine- 35 S. Since the decrease in intracellular specific activity was approximately the same in the types of leukocytes studied, a comparison between these groups remains valid. This may not be true, however, in other instances in which distribution ratios were compared on the basis of radioactivity alone [11,17,21,29].…”

Section: Discussionmentioning

confidence: 97%

“…Glutathione-35 S-NEM migrates so close to cysteine-3 »S-NEM in the electrophoretic system commonly used ( fig. 2) that if it were formed in other tissues, it could easily be regarded as cysteine- 35 S-NEM in studies of cyst(e)ine-35 S transport [21]. We have observed similar incorporation of cysteine- 35 S into glutathione-35 S in cultured human skin fibroblasts [24].…”

Section: Discussionmentioning

confidence: 99%

“…The differences in distribution ratios would be most meaningful if the intracellular 35 S in both normal and cystinotic cells remained as cysteine- 35 S, the form present in the incubation media, and the predominant intracellular form of this amino acid in all tissues previously studied [7,21]. Separation of intracellular components by high voltage electrophoresis on paper, 35 S. The two isomers of cysteine-NEM elute separately in this system [8].…”

Section: Fate Of Intracellular Cysteinementioning

confidence: 96%

See 1 more Smart Citation

Transport and Intracellular Fate of Cysteine-35S in Leukocytes from Normal Subjects and Patients with Cystinosis

1968

Pediatr Res

View full text Add to dashboard Cite

The transport and intracellular fate of cysteine-35 S was studied in leukocytes from nine children with cystinosis and nine control subjects of similar age in an attempt to explain the presence of 80 times the normal quantity of free cystine in cystinotic leukocytes. Two differences were observed: the cystin- SpeculationThe increased uptake of cysteine-35 S shown by cystinotic leukocytes could be taken as valid conventional evidence for a primary defect in the transport of cysteine in cystinosis. The prompt appearance of the extra 35 S transported as intracellular cystine-3S S suggests, however, that this rapid conversion may be the primary defect and that the increased uptake of cysteine-35 S is but a compensatory mechanism for maintaining the physiological concentration of intracellular cysteine.

show abstract

Intestinal Transport of Cystine and Cysteine in Man: Evidence for Separate Mechanisms*

Cited by 55 publications

References 11 publications

The Biosynthesis of Cystathionine in Patients with Homocystinuria

The Biosynthesis of Cystathionine in Patients with Homocystinuria

Comparison between SLC3A1 and SLC7A9 Cystinuria Patients and Carriers

Transport and Intracellular Fate of Cysteine-35S in Leukocytes from Normal Subjects and Patients with Cystinosis

Contact Info

Product

Resources

About