Comparison of N-Acetyl-L-Cysteine and L-Cysteine in Respect to Their Transmembrane Fluxes
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Tarih
2009
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Springer Heidelberg
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
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.
Açıklama
Anahtar Kelimeler
cysteine, N-acetyl-L-cysteine (NAC), erythrocytes, transmembrane transport
Kaynak
Biochemistry Moscow Supplement Series A-Membrane and Cell Biology
WoS Q Değeri
N/A
Scopus Q Değeri
Q4
Cilt
3
Sayı
2
