RESUMO
<p><b>OBJECTIVE</b>To study the effect of polydatin on phospholipase A(2) in lung tissues in rats with endotoxic shock.</p><p><b>METHODS</b>Thirty-two healthy male Wistar rats were employed in this study. A total of 8 rats received normal saline intravenously (control group), 8 rats received 10 mg/kg of endotoxin (endotoxic shock group), 8 rats received 1 mg/kg of polydatin after endotoxin injection (polydatin treatment group), and 8 rats received 1 mg/kg of polydatin (polydatin prevention group) 30 minutes before endotoxin injection. Mean arterial pressure was measured once half an hour. Lung tissues were collected 6 hours later. Phospholipase A(2) activity was measured with acid titration. The gene expression of secretory phospholipase A(2) type IIA was detected with reverse transcription polymerase chain reaction. Meanwhile, the histological changes of the lungs among four groups were compared through microscopic examination.</p><p><b>RESULTS</b>Phospholipase A(2) activity and the gene expression of secretory phospholipase A(2) type IIA increased after endotoxin injection, but polydatin could inhibit these effects of endotoxin. Obvious morphological evidence could be found in the lung pathological sections and the protective effect of polydatin was most significant in the polydatin prevention group.</p><p><b>CONCLUSIONS</b>Polydatin has prophylactic and therapeutic effects (the former is more distinct than the latter) on acutely injured lungs in rats with endotoxic shock and which suggests that polydatin may be a phospholipase A(2) inhibitor.</p>