In vitro exposure to carbon dioxide induces oxidative stress in human peritoneal mesothelial cells

Abstract

Background: The objective of this study was to verify whether in vitro exposure of human peritoneal mesothelial cells to carbon dioxide (CO2) influences the levels of 8-isoprostaglandin F2α (8-iso-PGF2α), a marker of oxidative stress. Methods: Mesothelial cells were exposed to either: (i) 100% CO2 for 4 h; (ii) 100% helium (an alternative gas with which to create hypoxic conditions) for 4 h; (iii) 100% CO2 for 24 h; or (iv) standard conditions (control). After gas exposure, mesothelial cells were returned to standard conditions and harvested immediately (T0), and at 1-(T1) and 3 (T3) h afterwards. Cell viability and culture medium pH were monitored throughout the experiments. 8-iso-PGF2α was assayed by enzyme-linked immunosorbent assay (ELISA). Results: Exposure to CO2 decreased the culture medium pH whereas helium increased the pH. 8-iso-PGF2α levels in all treated groups were significantly higher than in the control group: in the 4 h CO2 group at T1; in the 24 h CO2 group at T0 and T1; and in the 4 h helium group at T0, T1, and T3. 8-iso-PGF2α levels following 4 h CO2 exposure were significantly lower than after 24 h CO2 exposure at T1, and lower than following 4 h helium exposure at all time points. Conclusion: Exposure to both CO2 and helium induces oxidative stress in mesothelial cells. Hypoxia-reoxygenation may play a role in this process. © European Society of Human Reproduction and Embryology, 2004; all rights reserved.