Ultracytochemical demonstration of soluble guanylate cyclase activation in rat aorta by NCX4016, a NO-releasing aspirin derivative

In thoracic aorta of normal rats, soluble Guanylate Cyclase (sGC) activity was studied after stimulation with a nitro-derivative of aspirin (NCX4016) and sodium nitroprusside, a known activator of sGC. To demonstrate this enzymatic activity, we employed an ultracytochemical method for electron microscopy. Both NO-donors stimulated sGC in smooth muscle cells, and particularly in vascular endothelial cells. In a parallel study, we documented the protective effect of NCX4016 in vascular endothelium of diabetic rats (Ambrosini et al. in press). Therefore, we can hypothesize that, in diabetic rats, the protective effect of NCX4016 on the endothelium, is mediated by the activation of sGC.