Learn More
  • Deniz Yildiz
  • 2004
Nicotine is a naturally occurring alkaloid found in many plants. The principal sources of nicotine exposure is through the use of tobacco, nicotine containing gum and nicotine replacement therapies. Nicotine is an amine composed of pyridine and pyrrolidine rings. It has been shown that nicotine crosses biological membranes and the blood brain barrier(More)
OBJECTIVE The objective of the present study was to investigate if arsenate V exposure results in glutathione efflux from human erythrocytes. PROCEDURE The changes in intracellular and extracellular nonprotein sulfhydryl and glutathione levels were determined in arsenate (V) exposed erythrocytes. Presence of any cellular membrane damage was assessed by(More)
There have been several attempts to prevent the tumor growth and the resulting death. However, almost none of the developed methods designed to inhibit tumor growth gives a satisfactorily result without deleterious side effects. Some of the existing methods employed on prevention of tumor growth and invasion target the metabolic differences between normal(More)
The objective of the present study was to investigate if arsenic exposure results in glutathione efflux from human erythrocytes. Arsenite significantly depleted intracellular nonprotein thiol level in a time- and concentration-dependent manner. The intracellular nonprotein thiol level was decreased to 0.767 ± 0.0017 μmol/ml erythrocyte following exposure to(More)
The objective of this study was to investigate if erythrocytes play a role in the maintenance of redox homeostasis of the plasma. Thus, we studied L-cysteine efflux and influx in vitro in human erythrocytes. In the present study, we exposed the erythrocytes to different concentrations of L-cysteine and then measured the intracellular free -SH(More)
Nicotine and smokeless tobacco extract have been shown to induce oxidative stress in different experimental systems. However, the effect of nicotine and smokeless tobacco extract containing equal amounts of nicotine on 8-OH-dG formation has not been investigated. 8-OH-dG is a DNA adduct formed by free radical attack and is elevated in tumor cells. The(More)
The photosensitized generation of singlet oxygen within tumor tissues during photodynamic therapy (PDT) is self-limiting, as the already low oxygen concentrations within tumors is further diminished during the process. In certain applications, to minimize photoinduced hypoxia the light is introduced intermittently (fractional PDT) to allow time for the(More)
The main objective of the present study was to investigate if vanadate is extruded from the cells in a glutathione dependent manner resulting in the appearance of extracellular glutathione and complexes of glutathione with vanadium. Vanadate significantly depleted intracellular non-protein sulfhydryl (NPSH) levels in a time- and concentration-dependent(More)
There have been several attempts to prevent tumor formation and growth. However, none of the developed methods gives a completely satisfying result for the treatment of tumor masses. The most often used therapies against tumor cells are radiotherapy and chemotherapy. However, utilization of these methods to treat cancer generally result in generation of(More)
In previous studies, the transport of dinitrophenyl-glutathione from erythrocytes has been extensively investigated. However, the effect of treatment of erythrocytes with such xenobiotics on free-SH status of cells has not been well documented. Also, the effects of N-acetyl-L-cysteine or other-SH containing compounds on glutathione conjugate transport have(More)