Potential of lysophosphatidylinositol as a prognostic indicator of cardiac arrest using a rat model

Aims: The potential of a lysophosphatidylinositol species, LPI(18:0), as a biomarker of ischaemia was tested using a rat model of cardiac arrest (CA). Methods: Male Sprague-Dawley rats were subjected to asphyxia-induced CA or CA followed by cardiopulmonary bypass (CPB) resuscitation. The brain, heart, kidney and liver tissues were harvested from rats after 0, 5, 10, 20, 30 and 60 min CA and 30 min CA followed by 60 min CPB resuscitation. Blood samples were collected from inferior vena cava and hepatic veins following 30 min CA. Phospholipids were extracted from the four tissues and blood and analysed by HPLC-MS. Results: The relative content of LPI(18:0) compared to a phosphatidylinositol species, PI(18:0,22:4), was significantly increased in the brain, heart, liver and kidney following 30 min CA and decreased following CPB resuscitation. In addition, the increase of the LPI(18:0)/PI(18:0,22:4) ratio in the four tissues was proportional to the duration of ischaemia for CA lasting up to 60 min. The ratio was also found to be increased in plasma from the hepatic vein following 30 min CA. Conclusion: LPI(18:0) is a good indicator of CA downtime and has a potential to be used for early prognostication of outcome in CA.