The major aim of this study was to quantitatively assess the contribution of H2O2 generation to the cytotoxicity induced by cysteamine. Cysteamine produces H2O2 at levels that correlate with its toxicity between 23 and 160 microM. A maximum of 6.9 microM H2O2 is generated by 625 microM cysteamine. When compared to the toxicity of exogenous H2O2, cysteamine-derived peroxide accounted for 57% of ...

OBJECTIVE Cystinosis causes renal and other organ failure. Treatment with 6-hourly cysteamine bitartrate (Cystagon, Mylan, Morgantown, West Virginia) reduces intracellular cystine and the rate of organ deterioration. A recent study showed that an enteric-release cysteamine required less frequent daily dosing. This report describes the long-term use of enteric-coated (EC) cysteamine bitartrate (...

INTRODUCTION Cystinosis is a rare autosomal recessive disorder characterized by the intralysosomal accumulation of cystine. Cysteamine removes cystine from the lysosome and slows down the progression of the disease. One of its side effects is the induction of halitosis, which can interfere with patients' willingness to comply with cysteamine treatment. OBJECTIVE To identify breath sulphur com...

Cysteamine (300 mg/kg) administered subcutaneously depletes pancreatic somatostatin to 36% of control levels, but does not alter pancreatic insulin or glucagon content. Although perfusion of pancreata from normal animals with glucose (300 mg/dl) markedly stimulated somatostatin release, pancreata from cysteamine-treated animals failed to secrete somatostatin in response to glucose. Cysteamine t...

Chinese hamster ovary cells were exposed to the sulfhydryl compound cysteamine at concentrations ranging from 0 to 8 mM for 120 min. No toxicity was found in cells maintained at 5 degrees during treatment; however, at 37 degrees and 44 degrees a paradoxical toxicity was observed, i.e., substantial toxicity was observed at cysteamine concentrations of 0.2 to 1 mM but decreased at higher drug con...

The effect of cysteamine, a specific somatostatin depletor, on biliary secretion was studied in urethane-anesthetized rats. Different groups of rats received ip cysteamine at 25, 100 or 340 mg/kg just before bile collection commenced. Other groups of rats were pretreated with cysteamine (340 mg/kg ip) at 4 or 24 h prior to bile duct cannulation and bile collection. Bile secretions were collecte...

Both KB-5492, a new anti-ulcer agent, and cimetidine, administered orally at 25-200 mg/kg, dose-dependently prevented cysteamine (400 mg/kg, s.c.)-induced duodenal ulcers in rats with ED50 values of 63 and 40 mg/kg, respectively. Anti-ulcer doses of cimetidine, but not KB-5492, inhibited gastric acid hypersecretion induced by cysteamine (400 mg/kg, s.c.). In contrast, anti-ulcer doses of KB-549...

Cysteamine administration to rats is followed by a high incidence of peptic ulceration. The aim of the present study was to investigate the effect of cysteamine on gastric and duodenal mucosal histamine and gastric mucosal histamine formation capacity. After a four hour fast, cysteamine in doses of 50, 100, 200, 300, 400, and 500 mg/kg bodyweight was injected subcutaneously to male Wistar rats;...

To determine the effect of verapamil on experimental duodenal ulcer, pathologic assessment and secretory study were performed in the rats with ulcerogenic dose of cysteamine. The cysteamine increased gastric acid secretion and produced double duodenal ulcers at the proximal protion of the duodenum. Intramuscular injection of verapamil, 3 hours later, produced a significant decreased in gastric ...

BACKGROUND The full burden of nephropathic cystinosis in adulthood and the effects of long-term oral cysteamine therapy on its nonrenal complications have not been elucidated. OBJECTIVE To assess the severity of cystinosis in adults receiving and not receiving oral cysteamine therapy. DESIGN Case series. SETTING National Institutes of Health Clinical Center. PATIENTS 100 persons (58 men...