Cysteamine-d4 is intended for use as an internal standard for the quantification of cysteamine (hydrochloride) by GC- or LC-MS. Cysteamine is a stable aminothiol with radioprotective activities.1 It reduces ionizing radiation-induced death and chromosomal damage in mice in a dose-dependent manner.1,2 Cysteamine binds rapidly and temporarily to plasma proteins upon administration and this activity is directly correlated to its radioprotective effects.2 In vitro, 0.1 mM cysteamine depletes 90% of free cystine from cystinotic fibroblasts.3 Formulations containing cysteamine have been used to treat nephropathic cystinosis and reduce glomerular deterioration in humans.
1.Nelson, A.The protective effect of cysteamine on young mice exposed to roentgen raysActa. Radiol.42(6)485-493(1954) 2.Devik, F., and Lothe, F.The effect of cysteamine, cystamine and hypoxia on mortality and bone marrow chromosome aberrations in mice after total body roentgen irradiationActa. Radiol.44(3)243-248(1955) 3.Thoene, J.G., Oshima, R.G., Crawhall, J.C., et al.Cystinosis. Intracellular cystine depletion by aminothiols in vitro and in vivoJ. Clin. Invest.58(1)180-189(1976)