The antioxidant butylated hydroxytoluene (BHT) inhibits the dioctanoylglycerol-evoked platelet response but potentiates that elicited by ionomycin

Effects of anticoagulants and storage conditions on clinical oxylipid levels in human plasma

Metabolomics and lipidomics are of fundamental importance to personalized healthcare. Particularly the analysis of bioactive lipids is of relevance to a better understanding of various diseases. Within clinical routines, blood derived samples are widely used for diagnostic and research purposes. Hence, standardized and validated procedures for blood collection and storage are mandatory, in order to guarantee sample integrity and relevant study outcomes. We here investigated different plasma storage conditions and their effect on plasma fatty acid and oxylipid levels. Our data clearly indicate the importance of storage conditions for plasma lipidomic analysis. Storage at very low temperature (-80 °C) and the addition of methanol directly after sampling are the most important measures to avoid ex vivo synthesis of oxylipids. Furthermore, we identified critical analytes being affected under certain storage conditions. Finally, we carried out chiral analysis and found possible residual enzymatic activity to be one of the contributors to the ex vivo formation of oxylipids even at -20 °C.

Psoralen-fatty acid cycloadducts activate protein kinase C (PKC) in human platelets

The C4-photocycloadduct psoralen-linolenic acid activates protein kinase C (PKC), in human platelets, which in turn phosphorylates 47 kDa protein, representing its major substrate in these cells. This behaviour is similar to that shown by diacylglycerol, a main second messenger responsible of various biological effects, e.g. of melanogenesis.