title: Effects of cysteamine on oxidative status in cerebral cortex of rats.
abstract: Cystinosis is a systemic genetic disease caused by a lysosomal transport deficiency accumulating cystine in most tissues. Tissue damage depends on cystine accumulation, but the mechanisms of this damage are still obscure. Cysteamine administration depletes cystine accumulated, increasing survive of affected patients. Studies performed in fibroblasts of cystinotic patients suggest that apoptosis is enhanced in this disease. Considering that oxidative stress is a known apoptosis inducer, our main objective was to investigate a possible antioxidant effect of cysteamine on several parameters of oxidative stress in the brain of young rats. Animals received three subcutaneous injections at 3-h intervals of a buffered solution (pH 7.4) of 10 mg/kg body weight cysteamine and were sacrificed 1 h after the last injection. Cysteamine decreased lipoperoxidation and glutathione peroxidase activity, and increased the carbonyl content of proteins and catalase activity. In vitro studies showed that cysteamine reduced lipoperoxidation, 2',7'-dihydrodichlorofluorescein oxidation, carbonyl content of proteins and catalase activity, and increased glutathione peroxidase activity. These results suggest that cysteamine may act as a scavenger of superoxide free radicals and hydrogen peroxide. Therefore, it is possible that cysteamine may extend life of cystinotic patients acting not only as a cystine depleting drug, but also as a free radical scavenger, reducing cell damage by apoptosis.
authors.affiliation: Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, CEP 90.035-003, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Kessler
authors.forename: Micheli
authors.initials: M
authors.lastname: Biasibetti
authors.forename: Luciane Rosa
authors.initials: LR
authors.lastname: Feksa
authors.forename: Virginia Cielo
authors.initials: VC
authors.lastname: Rech
authors.forename: Denizar Alberto da Silva
authors.initials: DA
authors.lastname: Melo
authors.forename: Moacir
authors.initials: M
authors.lastname: Wajner
authors.forename: Carlos Severo
authors.initials: CS
authors.lastname: Dutra-Filho
authors.forename: Angela Terezinha de Souza
authors.initials: AT
authors.lastname: Wyse
authors.forename: Clovis Milton Duval
authors.initials: CM
authors.lastname: Wannmacher
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D003543:Cysteamine / Q000494:pharmacology*; D005452:Fluoresceins; D005456:Fluorescent Dyes; D005979:Glutathione Peroxidase / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D050050:Protein Carbonylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: C109098:2,7-dihydrodichlorofluorescein diacetate; D005452:Fluoresceins; D005456:Fluorescent Dyes; D017392:Thiobarbituric Acid Reactive Substances; D003543:Cysteamine; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase