ABSTRACT
<p><b>BACKGROUND</b>Acute lung injury (ALI) is a common syndrome associated with high morbidity and mortality in emergency medicine. Cell apoptosis plays a key role in the pathogenesis of ALI. Hydrogen sulfide (H(2)S) plays a protective role during acute lung injury. We designed this study to examine the role of H(2)S in the lung alveolar epithelial cell apoptosis in rats with ALI.</p><p><b>METHODS</b>Sixty-nine male Sprague Dawley rats were used. ALI was induced by intra-tail vein injection of oleic acid (OA). NaHS solution was injected intraperitonally 30 minutes before OA injection as the NaHS pretreatment group. Single sodium hydrosulfide pretreatment group and control group were designed. Index of quantitative assessment (IQA), wet/dry weight (W/D) ratio and the percentage of polymorphonuclear leukocyte (PMN) cells in the bronchoalveolar lavage fluid (BALF) were determined. H(2)S level in lung tissue was measured by a sensitive sulphur electrode. Apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and Fas protein was measured by immunohistochemical staining.</p><p><b>RESULTS</b>The level of endogenous H(2)S in lung tissue decreased with the development of ALI induced by OA injection. Apoptosis and Fas protein in alveolar epithelial cells increased in the ALI of rats but NaHS lessened apoptosis and Fas protein expression in alveolar epithelial cells of rats with ALI.</p><p><b>CONCLUSION</b>Endogenous H(2)S protects rats from oleic acid-induced ALI, probably by inhibiting cell apoptosis.</p>
Subject(s)
Animals , Male , Rats , Acute Lung Injury , Drug Therapy , Metabolism , Apoptosis , Physiology , Epithelial Cells , Hydrogen Sulfide , Metabolism , In Situ Nick-End Labeling , Oleic Acid , Toxicity , Rats, Sprague-Dawley , Sulfides , Pharmacology , Therapeutic UsesABSTRACT
Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are associated with high rates of morbidity and mortality. Currently, several surfactant or anti-inflammatory drugs are under test as treatments for ALI. Sodium aescinate (SA) has been shown to exert anti-inflammatory and antiedematous effects. In the present work, the authors explored the effects of SA and the possible mechanisms of SA action in rats with ALI induced by oleic acid (OA) administration. Eight groups of rats received infusions of normal saline (NS) or OA. Rats exposed to OA were pretreated with 1 mg/kg of SA, or posttreated with SA at low (1 mg/kg), medium (2 mg/kg), or high (6 mg/kg) dose; a positive-control group received methylprednisolone. The pressure of oxygen in arterial blood (P(O(2))) levels, the pulmonary wet/dry weight (W/D) ratios, and indices of quantitative assessment (IQA) of histological lung injury were obtained 2 or 6 hours after OA injection (0.1 mL/kg, intravenously). The levels of superoxide dismutase (SOD), malondialdehyde (MDA), matrix metalloproteinase gelatinase B (MMP-9), and tissue inhibitor of metalloproteinase (TIMP-1) in both plasma and lung tissue were also determined. Both pre- and posttreatment with SA improved OA-induced pulmonary injury, increased P(O(2)) and SOD values, lowered IQA scores, and decreased the lung W/D ratio and MDA and MMP-9 levels in plasma and lung tissue. SA appeared to abrogate OA-induced ALI by modulating the levels of SOD, MDA, and MMP-9 in plasma and lung tissue.
