S-NITROSOHEMOGLOBIN - A DYNAMIC ACTIVITY OF BLOOD INVOLVED IN VASCULAR CONTROL

A dynamic cycle exists in which haemoglobin is S-nitrosylated in the l ung when red blood cells are oxygenated, and the NO group is released during arterial-venous transit. The vasoactivity of S-nitrosohaemoglob in is promoted by the erythrocytic export of S-nitrosothiols. These fi ndings highlight newly discovered allosteric and electronic properties of haemoglobin that appear to be involved in the control of blood pre ssure and which may facilitate efficient delivery of oxygen to tissues . The role of S-nitrosohaemoglobin in the transduction of NO-related a ctivities may have therapeutic applications.