4HNE treatment increases mitochondrial mass. HL1 Cardiomyocytes were treated with 50 μM 4HNE and/or 10 μM carvedilol. (a, b) 4HNE increased flow cytometric signal of Mitotracker Red CMXRos, a measure of mitochondrial mass (N=4/group). (c, d) 4HNE increased VDAC1 expression, another marker of mitochondrial mass, but this was inhibited by carvedilol. (e) 4HNE did not decrease PGC1α expression, a marker of mitochondrial biogenesis (N=3/group). 4HNE - 4-hydroxynonenal; Carv – carvedilol; FSC – forward scatter. Data are presented as mean±SEM. **p<0.01.