[Biological role of metabolic pathways from L-arginine to nitric oxide]

This paper reviews recent developments in the biochemistry, pharmacology and physiology of the L-arginine/nitric oxide pathway. Nitric oxide accounts for the biological activity of endothelium-derived relaxing factor (EDRF) and its continuous release plays a crucial role in the regulation of vascular tone and platelet activity. In the nervous system nitric oxide is a neurotransmitter. In the peripheral nervous system, nitroxergic nerves form a part of the non-adrenergic, non-cholinergic innervation of the visceral organs. In the immune system, nitric oxide generated by activated macrophages has tumoricidal and antimicrobial activities. Growing evidence suggests that the alterations in the formation of NO in various tissues contribute to the pathogenesis of various diseases, including hypertension, atherosclerosis, diabetes, subarachnoid hemorrhage and septic shock. Therefore, the improvements in our understanding of the regulation of L-arginine/nitric oxide pathway on the molecular level may lead to the development of new drugs.