Effects of formaldehyde on the levels of NOS isoforms and the generation of NO in PC12 cells.

After treatment of PC12 cells with 60, 120, and 240 µmol/L of FA for 24 h, respectively, the levels of NOS isoforms in PC12 cells (A) and the content of NO in cell medium (B) were determined by ELISA kit and NO kit, respectively. Values are expressed as the mean ± SEM of three independent experiments. ^**P<0.01, ^***P<0.001, vs vehicle group (control).