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BACKGROUND: The present study was undertaken to examine the regulatory effect of hydrogen sulfi de (H 2 S) on endoplasmic reticulum stress in alveolar epithelial cells of rats with acute lung injury (ALI) induced by oleic acid (OA).METHODS: Seventy-two male Sprague Dawley (SD) rats were divided into control group, oleic acid-induced ALI group (OA group), oleic acid-induced ALI with sodium hydrosulfide (NaHS) pretreatment group (OA+NaHS group), and sodium hydrosulfide treatment group (NaHS group). Rats of each group were further subdivided into 3 subgroups. Index of quantitative assessment of histological lung injury (IQA), wet/dry weight ratio (W/D) and H 2 S level of lung tissues were measured. The expressions of endoplasmic reticulum stress markers including glucose-regulated protein 78 (GRP78) and α-subunit of eukaryotic translation initiation factor-2 (elF2α) in lung tissues were measured by immunohistochemical staining and Western blotting. RESULTS:The IQA score and W/D ratio of lung tissues at the three time points significantly increased in rats injected with OA, but significantly decreased in other rats injected with OA and NaHS. The level of H 2 S in lung tissue at the three time points signifi cantly decreased in rats injected with OA, but signifi cantly increased in other rats injected with both OA and NaHS. GRP78 and elF2α decreased in rats injected with OA, but increased in other rats injected with both OA and NaHS, especially at 4-hour and 6-hour time points. CONCLUSION:The results suggested that H 2 S could promote alveolar epithelial cell endoplasmic reticulum stress in rats with ALI.

The heat capacity of poly(vinyl methyl ether) (PVME)/water mixtures was measured over a wide range of temperatures using the stepscan method. The results showed that water exists in different states in the mixtures. The C p values of dry PVME and PVME/ water mixtures with a low water content were obtained by the stepscan method, and the C p of bound water in the mixtures was approximated. The results showed that the C p of bound water in the mixtures with a low water content is higher than that of mixtures with glassy water and ice, and it shows no dependence on water content in the glassy state. Because of the larger conformational contribution to C p , the heat capacity of water in the mixtures in the liquid state increases with water content. Because there is a weak interaction between PVME and water molecules, the structure of water in mixtures is different from that of glassy water. The C p value of unfreezable bound water in the mixtures was calculated without considering the effect of polymer content, and the interaction between PVME and water was obtained; these calculations explained the phase separation observed at high temperature. Polymer Journal (2010) 42, 540-545; doi:10.1038/pj.2010.37; published online 5 May 2010Keywords: DSC; glassy water; phase separation; stepscan INTRODUCTION Water-soluble polymer solutions have recently aroused a great deal of interest among research studies for use in academic and industrial applications. 1,2 Aqueous polymers have numerous applications in scientific and industrial areas, such as food and/or pharmaceutical applications. Aqueous polymer solutions have exhibited peculiar and complicated behaviors, such as depressed melting point and crystallization temperature of water in aqueous polymer solutions and unusual phase behavior. At the same time, some aqueous polymer water solutions exhibit phase separations above the lower critical solution temperature and closed loop phase behavior, which are characteristics of polymer solutions that exhibit hydrogen bonding. 3,4 Poly(vinyl methyl ether) (PVME) is a classical example of a polymer presenting an lower critical solution temperature at a moderate temperature range of around 35 1C, 5,6 above which the solution separates into two phases. It has been shown that, in aqueous solution, the ether functions of repeat units in the PVME molecule form a complex with water molecules. Maeda 7 proposed a formation of a stable molecular complex with 2.7 molecules of water per repeat unit of PVME. At a higher overall water content, a higher degree of hydration was achieved with up to five water molecules per repeat unit of PVME.

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Background/Aims: In the present study, we explored reactive axygen species (ROS) production in mitochondria, the mechanism of hexavalent chromium (Cr(VI)) hepatotoxicity, and the role of protection by GSH. Methods: Intact mitochondria were isolated from rat liver tissues and mitochondrial basal respiratory rates of NADH and FADH₂ respiratory chains were determined. Mitochondria were treated with Cr(VI), GSH and several complex inhibitors. Mitochondria energized by glutamate/malate were separately or jointly treated with Rotenone (Rot), diphenyleneiodonium (DPI) and antimycinA (Ant), while mitochondria energized by succinate were separately or jointly treated with Rot, DPI ‚ thenoyltrifluoroacetone (TTFA) and Ant. Results: Cr(VI) concentration-dependently induced ROS production in the NADH and FADH₂ respiratory chain in liver mitochondria. Basal respiratory rate of the mitochondrial FADH₂ respiratory chain was significantly higher than that of NADH respiratory chain. Hepatic mitochondrial electron leakage induced by Cr(VI) from NADH respiratory chain were mainly from ubiquinone binding sites of complex I and complex III. Conclusion: Treatment with 50µM Cr(VI) enhances forward movement of electrons through FADH₂ respiratory chain and leaking through the ubiquinone binding site of complex III. Moreover, the protective effect of GSH on liver mitochondria electron leakage is through removing excess H₂O₂ and reducing total ROS.