Cobalt stimulates the expression of vascular endothelial growth factor mRNA in rat cardiac cells.

We have previously demonstrated that an exposure of rat cardiomyocytes to anoxia induces the expression of mRNAs coding for vascular endothelial growth factor (VEGF). The action of anoxia was mimicked by Co, Ni and Mn. The actions of Co and of anoxia were not additive and did not involve AP-1 binding sites. Experiments using actinomycin D and cycloheximide indicated that VEGF mRNA levels in cardiac cells are regulated both at transcriptional and post transcriptional levels. It is concluded that an oxygen sensing mechanism is present in cardiac cells and controls the expression of VEGF mRNAs. It may be important for the neovascularization of ischemic myocardium.