Fig. 1

The effects of nitric oxide. Nitric oxide (NO) is an important vasodilator synthesised from L-arginine via endothelial nitrogen oxide synthase (eNOS). NO activates guanylyl cyclise, leading to elevated concentrations of cyclic guanosine monophosphate (cGMP) and the downstream activation of cGMP-dependent protein kinase. This enzyme mediates a significant reduction in intracellular Ca²⁺concentration and decreased vascular tone, resulting in vascular smooth muscle relaxation. Simultaneously, NO inhibits the aggregation of platelets, vascular smooth muscle cell proliferation, thrombus formation and ameliorates the adhesion capabilities of leukocytes