Cysteamine prevents inhibition of thiol-containing enzymes caused by cystine or cystine dimethylester loading in rat brain cortex.

Cystinosis is a systemic genetic disease caused by a lysosomal transport deficiency accumulating cystine in the lysosomes of all tissues. Although tissue damage might depend on cystine accumulation, the mechanisms of tissue damage are still obscures. Considering that thiol-containing enzymes are critical for several metabolic pathways, our main objective was to investigate the effects of cystine or cystine dimethylester load on the thiol-containing enzymes creatine kinase and pyruvate kinase, in the brain cortex of young Wistar rats.

Inhibition of creatine kinase activity by cystine in the kidney of young rats.

Nephropathic cystinosis is a lethal genetic disease caused by a lysosomal transport disorder leading to intralysosomal cystine accumulation in all tissues. Cystinosis is the most common inherited cause of Fanconi syndrome, but the mechanisms by which cystine causes tissue damage are not fully understood. Thiol-containing enzymes are critical for renal energy metabolism and may be altered by disulfides like cystine.