Formaldehyde (FA) has been linked to the detrimental cardiovascular effects. Here, we explored the effects and mechanisms of FA on rat aortas both in vivo and in vitro. The results presented that FA evidently lowered the blood pressures of rats. The expression levels of BKCasubunits αand β1 and iNOS of the aortas were up-regulated by FA in vivo. However, FA markedly reduced the levels of Cav1.2 and Cav1.3, which are the subunits of L-Ca2+channel. Furthermore, the contents of NO, cGMP and iNOS in the aortas were augmented by FA. To further confirm these findings, the mechanisms accre...