The regulation of lysosomal cystine transport was studied using cystine dimethyl ester-loaded lysosomes isolated from human diploid fibroblasts. Net efflux from normal fibroblast lysosomes was compared to that from lysosomes of cystinotic fibroblasts, which contain an inherited mutation decreasing lysosomal cystine transport. This exodus of cystine from normal fibroblast lysosomes was greater t...

The relation of the cystine of the diet to the growth and composition of the hair of young white rats has been established (l-3). In the absence of adequate amounts of dietary cystine, optimal growth of the hair was not observed and the cystine and sulfur contents of the hair were lower than those of rats maintained on diets supplying ample amounts of cystine. The ingestion of cystine in quanti...

The formation of various types of kidney stones is strongly influenced by urinary pH. An alkaline pH favors the crystallization of calcium- and phosphate-containing stones, whereas and acidic urine pH promotes uric acid or cystine stones. The activity of many transport processes involved in calcium, citrate and phosphate handling are sensitive to changes in systemic or local pH as shown for sev...

Alkalizing beverages are highly effective in preventing the recurrence of calcium oxalate (Ox), uric acid and cystine lithiasis. The aim of the present study was to evaluate the influence of grapefruit-juice and apple-juice consumption on the excretion of urinary variables and the risk of crystallization in comparison with orange juice. All investigations were carried out on nine healthy female...

Purpose To compare the results of a chemical method of kidney stone analysis with the results of Fourier transform infrared (FT-IR) spectroscopy. Materials and Methods Kidney stones collected between June and October 2015 were simultaneously analyzed by chemical and FT-IR methods. Results Kidney stones (n=449) were collected from patients from 1 to 81 years old. Most stones were from adults...

The urinary excretion of cystine, as determined on the polarograph, varies, in normal adults, between 40 and 80 mg. daily (1). It may be increased either as a result of a low renal threshold for cystine or a raised plasma cystine concentration. Cystinuria due to a low renal threshold occurs in 'classical cystinuria,' the Fanconi syndrome and hepatolenticular degeneration (2). In such conditions...

It is found that both the inward and outward transport of cystine and glutamate through the plasma membrane of cultured human fibroblasts is mediated mostly by a single transport system. Cystine and glutamate at one side of the membrane stimulate the passage of these amino acids present at the other side of the membrane. When the concentration of intracellular glutamate is reduced to near zero,...

The diagnostic usefulness of information regarding the chemical composition of renal stones has been recognized since the 1950s and has been significantly improved during last years [1—13]. So it is now possible to correlate the results of every analysis with the appropriate diagnosis and therapeutic regime. Nowadays, current physical and chemical methods available for urinary stones analysis a...

Lysosomal cystine transport is a carrier-dependent process that, in isolated lysosomes, is stimulated by proton gradients, membrane potential, and millimolar concentrations of divalent cations. The importance of these regulatory factors in vivo is not well established. Polyamines were found to stimulate cystine transport in Percoll gradient purified rat liver lysosomes with spermidine greater t...

The uptake of L-cystine or L-glutamate into cultured human diploid fibroblasts, IMR-90, has been studied. These amino acids appeared to be taken up into the cells via sodium ion-independent uptake system. Inhibition studies using various amino acids provided information about the specificity of the uptake system. The L-cystine or L-glutamate uptake system was shown to exhibit very similar subst...