Oxidative stress increases adrenomedullin mRNA levels in cultured rat vascular smooth muscle cells.

We investigated the effect of oxidative stress on the expression of adrenomedullin (AM) mRNA in cultured rat vascular smooth muscle cells (VSMCs), using diethyldithiocarbamate (DDC), which is known to inhibit endogenous Cu, Zn superoxide dismutase (SOD) and to increase superoxide (O2-). DDC (10 mM) increased O2- levels produced from rat VSMCs in a time-dependent fashion. Concomitantly, DDC increased the expression of AM mRNA for up to 24 h, although it did not affect the expression of beta-actin mRNA. Thus, oxidative stress enhanced AM production in rat VSMCs, which may compensate for oxidative-stress-induced vasoconstriction.