Platonin mitigates acute lung injury in haemorrhagic shock rats

Aim of the study: Enhanced oxidative stress and inflammatory response are crucial in mediating the development of acute lung injury induced by haemorrhagic shock with resuscitation. Platonin, a potent antioxidant, possesses potent anti-inflammation capacity. We sought to elucidate whether platonin could mitigate acute lung injury in haemorrhagic shock/resuscitation rats. Methods: Seventy-two adult male rats were randomized to receive haemorrhagic shock/resuscitation (HS), HS plus platonin (10, 50, or 100 μg/kg intravenous injection immediately after resuscitation), sham instrumentation (Sham), or Sham plus platonin (100 μg/kg) (n=12 in each group). Haemorrhagic shock was induced by blood drawing and mean blood pressure was maintained at 40-45. mmHg for 120. min. Then, resuscitation was achieved by shed blood/saline mixtures re-infusion. After monitoring for another 8. h, rats were sacrificed. Results: Arterial blood gas and histological findings, in concert with assays of leukocyte infiltration (polymorphonuclear leukocytes/alveoli ratio and myeloperoxidase activity) and lung water content (wet/dry weight ratio), confirmed that haemorrhagic shock/resuscitation caused significant lung injury. Significant increases in concentrations of inflammatory molecules (chemokine, cytokine, and prostaglandin E₂) as well as nitric oxide and malondialdehyde in lung tissues confirmed that haemorrhagic shock/resuscitation elicited inflammatory response and imposed oxidative stress in rats. Platonin at the dosages of 50 and 100μg/kg, but not 10μg/kg, significantly attenuated the inflammatory response and oxidative stress induced by haemorrhagic shock/resuscitation. Most important, platonin at the dosages of 50 and 100μg/kg, but not 10μg/kg, significantly mitigated the lung injury induced by haemorrhagic shock/resuscitation. Conclusions: Platonin mitigates acute lung injury in haemorrhagic shock/resuscitation rats.