S-methylthio-cysteine and cystamine are potent stimulators of thiol production and glutathione synthesis.
The effects of methylthio-cysteine disulfide (MT-Cy) and cystamine (CAM) on the thiol production and glutathione content of a human T cell line (CEM-SS) have been investigated. MT-Cy per se and CAM in the presence of cystine greatly enhanced thiol production and glutathione content of cells while cystine alone exerted no or slight influence in the first hours. The MT-Cy- or CAM-induced extracellular SH-generation was observed both in a complete nutrient medium and even more in SH-free D-PBS. The acid-soluble thiol level and glutathione content of cells elevated markedly (up to 5-6 fold in two hours) when incubating cells in complete medium. Inhibition of glutathione synthesis by DL-buthionine (S,R)-sulfoximine did not alter the MT-Cy- or CAM-induced extracellular thiol production indicating that glutathione synthesis is not involved in this effect. The results suggest that MT-Cy easily enters the cells thus accelerating the thiol cycle in SH-poor medium while CAM promotes cystine uptake into the cells. Phenylalanine and leucine inhibited both MT-Cy- and CAM-dependent thiol production in D-PBS most effectively suggesting the involvement of the L membrane transport system in these effects.
Jókay
I
I
Microbiological Research Group, National Institute of Hygiene, Budapest, Hungary. mini@microbi.hu
Kelemenics
K
K
Gyuris
A
A
Minárovits
J
J
D002460:Cell Line; D003538:Cystamine / Q000494:pharmacology*; D003545:Cysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D005978:Glutathione / Q000096:biosynthesis*; D006801:Humans; D013438:Sulfhydryl Compounds / Q000378:metabolism*
D013438:Sulfhydryl Compounds; C017115:S-methylthiocysteine; D005978:Glutathione; D003545:Cysteine; D003538:Cystamine