(A) Platelets were incubated with 4-HNE (HNE) (0–30 µM) for 1h after which a mitochondrial stress test was performed by first measuring basal OCR, followed by sequential injection of oligomycin (O) (1 µg/ml), FCCP (F) (0.6 µM), antimycin A (AA) (10 µM). Different indices of mitochondrial respiration (B) basal (basal OCR – AA OCR), (C) ATP-linked (AL) (basal OCR – oligomycin OCR), (D) proton leak (PL) (oligomycin OCR – AA OCR), (E) maximal (FCCP OCR – AA OCR), (F) reserve capacity (RC) (FCCP OCR – basal OCR) and (G) non-mitochondrial (NM) (AA OCR) were calculated. Data expressed as mean±SEM from one representative donor, n = 5–6 replicates. **p<0.01, different from thrombin.