Eritrositlerde L-sistein amino asit exportuna hücre içi ve dışı redoks durumunun etkisi

Abstract

1ÖZET(5ø7526ø7/(5'(/6ø67(ø1$0ø12$6ø7(;325781$+h&5(ødø9(',ù,5('2.6'85808181(7.ø6øGlutatyon, antioksidan savunmada önemli bir rol oynar. Bu nedenle glutatyon,eritrositlerde yüksek miktarlarda bulunur. L-sistein amino asidi, eritrositlerde glutatyonVHQWH]L LoLQ JHUHNPHNWHGLU %X oDOÃúPDQÃQ DPDFà KÂFUH LoL YH GÃúà redoks durumunun,eritrositlerde L-sistein HNVSRUWXQD HWNLVLQL LQFHOHPHNWLU dDOÃúPDGD HULWURVLWOHUL IDUNOÃkonsantrasyonlardaki L-sistein DPLQR DVLGLQH PDUX] EÃUDNÃOPÃú YH VRQUD GDHULWURVLWOHUGHNL VHUEHVW ±6+ NRQVDQWUDV/RQXQX OoÂOPÂúWÂU $/Qà /QWHPOH PXDPHOHedilen eritrositler, sonraki L-VLVWHLQ oÃNÃúà oDOÃúPDODUÃQGD NXOODQÃOPÃúWÃU $/Qà ]DPDQGDÃVÃQÃQ EX JLULúoÃNÃúD RODQ HWNLVL GH÷HUOHQGLULOPLúWLU øON RODUDN ELU glutatyon tüketicisiolan 1-chloro-2,4-dinitrobenzene ile muamele edilen eritrositlerde, buthionineVXOIR[LPLQHYDUOÃ÷ÃQGDYH/RNOX÷XQGD/VLVWHLQoÃNÃúÃQÃQQDVÃOHWNLOHQGL÷LEHOLUOHQPLúWLUL-VLVWHLQ JLULúL oDOÃúPDODUÃPÃ]GD SOD]PDGD /VLVWHLQ NRQVDQWUDV/RQX DUWWÃ÷ÃQGDHULWURVLWOHULQ EX DUWÃúD FHYDS YHUHUHN /sistein DPLQR DVLGLQL KÂFUH LoLQH DOGÃ÷ÃJVWHULOPLúWLU (ULWURVLWOHUGHNL VHUEHVW ±6+ NRQVDQWUDV/RQX P0 /sisteinX/JXODQGÃ÷ÃQGDVDDWWHÂP0¶D /ÂNVHOLUNHQEXNRQVDQWUDV/RQ P0 /VLVWHLQ X/JXODQGÃ÷ÃQGD  P0¶ D /ÂNVHOPLúWLU (ULWURVLWOHUGH VHUEHVW ±6+NRQVDQWUDV/RQODUà P0 /VLVWHLQ X/JXODQGÃ÷ÃQGD GDNLNDGD  P0¶ D/ÂNVHOLUNHQVDDWWHEXNRQVDQWUDV/RQÂP0¶D/ÂNVHOPLúWLU$/QÃ]DPDQGDL-sistein DPLQR DVLGLQLQ oÃNÃúÃQÃQ GD ]DPDQ YH NRQVDQWUDV/RQD ED÷Oà ROGX÷XEHOLUOHQPLúWLU <ÂNVHN PLNWDUGD /VLVWHLQOH PXDPHOH HGLOPLú HULWURVLWOHUGH /ÂNVHNmiktarda L-VLVWHLQoÃNÃúÃJUÂOÂUP0/sisteinle muamele edilen eritrositlerde, hücreGÃúÃVHUEHVW±6+NRQVDQWUDV/RQXVDDWWHÂP0¶D/ÂNVHOLUNHQP0/sisteinle muamele edilen eritrositlerde bu konsantrasyon 1,014 ± 0,002 mM' a/ÂNVHOPLúWLU Â& VÃFDNOÃN HULWURVLWOHUH /VLVWHLQ JLULúLQL WHVW HGLOHQ EÂWÂQkonsantrasyonlarda, önemli derecede LQKLEH HWPLúWLU 6ÃFDNOÃN DUWÃúà EX JLULú ROD/ÃQÃ/HQLGHQ GÂ]HOWPHNWHGLU %HQ]HU VRQXoODU oÃNÃú oDOÃúPDODUà LOH GH HOGH HGLOPLúWLU6RQXoODUÃPÃ] D/Qà ]DPDQGD /VLVWHLQLQ LoHUL YH GÃúDUà transportunun, eritrositinRNVLGDWLI GXUXPXQGDQ HWNLOHQGL÷LQL JVWHUPLúWLU *OXWDW/RQ WÂNHWLOGL÷LQGH YH glutatyonVHQWH]L HQJHOOHQGL÷LQGH /VLVWHLQLQ KÂFUH/H JLULúoÃNÃúà QHPOL GHUHFHGH D]DOPÃúWÃUEritrositler, plazma UHGRNV GXUXPXQXQ GHYDPà YH KÂFUH LoL JOXWDW/RQXQ EHOLUOHGL÷L /VLVWHLQoÃNÃúRUDQÃQGDUROR/QDU2006, 46 sayfaAnahtar Kelimeler: Eritrosit, 6LVWHLQoÃNÃúÃRedoks dengesi.

ABSTRACTTHE EFFECT OF INTRACELLULAR AND EXTRACELLULAR REDOX67$78621/&<67(ø1((;3257,1(5<7+52&<7(6Glutathione has an important role in antioxidant defense. For this reason,glutathione is found at rather high amounts in erythrocytes. L-cysteine is required forglutathione synthesis in erythrocytes. The objective of this study was to invastigate theeffect of intracellular and extracellular redoks status on L-cysteine exports inerythrocytes. In the present study, we exposed the erythrocytes to differentconcentrations of L-cysteine and then measured the intracellular free -SHconcentrations. The erythrocytes treated in the same manner were later utilized for thecysteine efflux studies. The effect of temperature on the influx and the efflux processeswere also evaluated. We also determined the rate of L-cysteine efflux in the presenceand absence of Buthionine Sulfoximine in erythrocytes that are pretreated with 1-chloro-2, 4-dinitrobenzene, a glutathione depleter.Our L-cysteine influx studies demonstrated that erythrocytes can respond toincreases in L-cysteine concentration in the extracellular media and influx L-cysteine ina concentration-dependent manner. Free -SH concentration in erythrocytes treated with1 mM L-cysteine reached to 1,64 ± 0,06 mM in 1 hour whereas this concentrationreached to 4,30 ± 0,01 mM in 10 mM L-cysteine treated erythrocytes. Free -SHconcentration in erythrocytes treated with 10 mM L-cysteine reach to 2,48 ± 0,09 mMin 10 minute whereas this concentration, when treated 10 mM L-cysteine in 1 hour,reach to 4,30 ± 0,01 mM. The L-cysteine efflux is also determined to be time andconcentration-dependent. Erythrocytes that are pretreated with higher L-cysteineconcentrations displayed a higher efflux process. Outside concentration of free -SH in 1mM L-cysteine pretreated erythrocytes, reach to 0,200 ± 0,005 mM in 1hour, whereasthis concentration reach to 1,014 ± 0,002 mM with 10 mM L-cysteine pretreatederythrocytes. The influx process is significantly inhibited +4 ºC at all of theconcentration tested. Increasing of the temperature later recovered the influx process.Similar results were obtained with the efflux studies. Our results also indicate that rateof inward and outward transport of L-cysteine is affected by the oxidative status oferythrocytes. When glutathione is depleted and glutathione synthesis is blocked, L-cysteine uptake and the efflux processes are significantly decreased. Erythrocytes play arole in regulation the plasma redoks status and intracellular level of glutathionedetermines the rate of the L-cysteine efflux.2006, 46 PagesKeywords: Erythrocytes, Cysteine efflux, Redox homeostasis