Increased glutathione conjugate transport: a possible compensatory protection mechanism against oxidative stress in obesity?

Özaydın A., Onaran I., Yesim T., Sargin H., Avsar K., Sultuybek G.

INTERNATIONAL JOURNAL OF OBESITY, cilt.30, ss.134-140, 2006 (SCI-Expanded, Scopus) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 30
  • Basım Tarihi: 2006
  • Doi Numarası: 10.1038/sj.ijo.0803108
  • Dergi Adı: INTERNATIONAL JOURNAL OF OBESITY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.134-140
  • İstanbul Üniversitesi-Cerrahpaşa Adresli: Evet

Özet

Objective: To compare glutathione S-conjugate transport in obese and nonobese persons, and how glutathione S-conjugates
are involved in the antioxidant status in obesity.
Materials and methods: The efflux of glutathione conjugates and malondialdehyde (MDA) levels were measured in
erythrocytes of obese (N¼33) and nonobese (N¼28) persons at every 30 min during a 120 min incubation time in vitro. 2,4-
dinitrophenyl-S-glutathione (DNP-SG) represented the glutathione S-conjugate.
Results: The efflux of conjugate in erythrocytes from obese subjects (7087147 DNP-SG efflux nmol/ml erythrocytes/h) was
significantly higher than that of control group (4907105 DNP-SG efflux nmol/ml erythrocytes/h) (Po0.05). At all time points
measured (30–120 min), there was an increase in DNP-SG efflux in obese group (Po0.05). This is manifested by a decrease in
cellular DNP-SG levels. The susceptibility of erythrocytes to in vitro 1-chloro-2,4-dinitrobenzene (CDNB)-induced oxidative stress
were greater for cells of control group (Po0.05), although hemolysis sensitivity of these cells are not different between both
groups (P40.05). Following CDNB pretreatment, incubation of erythrocyte with vanadate, a DNP-SG transport inhibitor,
resulted in an increase of MDA in both groups. However, in this case, the difference in susceptibility was not related to obesity.
On the other hand, while erythrocyte glutathione level was lower in obese subjects (79% of control) than in controls (Po0.05),
the adenosine 50-triphosphate (ATP) levels, the enzyme activities of glutathione S-transferase (GST) and the conjugation
capacities of the erythrocytes were not different between groups (P40.05).
Conclusion: Obesity may increase erythrocyte glutathione conjugate transport independent from ATP and GST activity that
may protect against MDA formation in vitro.