Yazar "Civi, Z." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ N/A ]
    Öğe
    COMPARISON OF N-ACETYL-L-CYSTEINE AND L-CYSTEINE IN RESPECT TO THEIR TRANSMEMBRANE FLUXES
    (Mezhdunarodnaya Kniga, 2009) Yildiz, D.; Arik, M.; Cakir, Y.; Civi, Z.
    The objective of the present study was to compare cysteine and N-acetyl-L-cysteine in respect to their transmembrane fluxes and find out which one is a better available precursor for the cells and thus better supports the intracellular glutathione synthesis. Cysteine can directly participate in glutathione synthesis, whereas N-acetyl-L-cysteine must be first deacetylated before its incorporation to glutathione. In the present study we investigated and compared the efficiencies of cysteine and N-acetyl-L-cysteine influx and efflux through the erythrocyte membrane. Erythrocytes transported both cysteine and N-acetyl-L-cysteine in a concentration-dependent manner. However, our results demonstrated that cysteine crosses the erythrocyte membranes more efficiently than N-acetyl-L-cysteine does. Treatment of erythrocytes with 5 mM of cysteine or N-acetyl-L-cysteine for 1 hr raised the intracellular free sulfhydryl group (free-SH) levels to 3.37 +/- 0.006 or 2.23 +/- 0.08 mu mol/ml erythrocyte, respectively. Cysteine more effectively than N-acetyl-L-cysteine restored the intracellular free-SH level lowered beforehand. In erythrocytes previously depleted of free-SH, 5 mM cysteine raised the free-SH level to 1.45 +/- 0.075 mu mole/ml within I hr, whereas N-acetyl-L-cysteine at the same concentration raised this level to 0.377 +/- 0.034 mu mole/ml only. The results of our study also revealed that both cysteine and N-acetyl-L-cysteine influx and efflux processes are temperature dependent, indicating that their transport requires biological activity. Our results demonstrate that cysteine is a better thiol precursor for the erythrocytes. Availability of cysteine for the cells is higher than that of N-acetyl-L-cysteine.
  • Küçük Resim
    Öğe
    Comparison of N-Acetyl-L-Cysteine and L-Cysteine in Respect to Their Transmembrane Fluxes
    (Springer Heidelberg, 2009) Yildiz, D.; Arik, M.; Cakir, Y.; Civi, Z.
    The objective of the present study was to compare cysteine and N-acetyl-L-cysteine in respect to their transmembrane fluxes and find out which one is a better available precursor for the cells and thus better supports the intracellular glutathione synthesis. Cysteine can directly participate in glutathione synthesis, whereas N-acetyl-L-cysteine must be first deacetylated before its incorporation to glutathione. In the present study we investigated and compared the efficiencies of cysteine and N-acetyl-L-cysteine influx and efflux through the erythrocyte membrane. Erythrocytes transported both cysteine and N-acetyl-L-cysteine in a concentration-dependent manner. However, our results demonstrated that cysteine crosses the erythrocyte membranes more efficiently as compared to N-acetyl-L-cysteine. Treatment of erythrocytes with 5 mM of cysteine or N-acetyl-L-cysteine for 1 hr raised the intracellular free sulfhydryl group (free-SH) levels to 3.37 +/- 0.006 or 2.23 +/- 0.08 mu mol/ml erythrocyte, respectively. Cysteine more effectively than N-acetyl-L-cysteine restored the intracellular free-SH level depleted beforehand. In erythrocytes previously depleted of free-SH, 5 mM cysteine raised the free-SH level to 1.45 +/- 0.075 mu mol/ml within 1 hr, whereas N-acetyl-L-cysteine at the same concentration raised this level to 0.377 +/- 0.034 mu mol/ml only. The results of our study also revealed that both cysteine and N-acetyl-L-cysteine influx and efflux processes are temperature dependent indicating that their transport requires biological activity. Our results demonstrate that cysteine is a better thiol precursor for the erythrocytes. Availability of cysteine for the cells is higher than that of N-acetyl-L-cysteine.