Efectos de la terapia estrogenica sustitutiva sobre la actividad de las sintasas de oxido nitrico

Nitric oxide (NO) is synthesized from the L-arginine aminoacid by a family of enzymes called NO synthases. The relationship between pregnancy, a state of increased estrogenic production, and the increase in circulating levels of NO is well known. This observation enabled the relationship between estrogen levels and the activity of nitroux oxides to be studied, both at an experimental level and in clinical studies. The results suggest that estrogens regulate the secretion of endothelial and neuronal NOS in these tissues. This newly discovered action of estrogens can be related to the known beneficial effects of estrogen replacement therapy on the risk of developing cardiovascular disease and of behaviour changes which present in menopausal women.