Red blood cell Much of this potential appears to be contributed by the exposed sialic acid residues in the membrane: their removal results in zeta potential of −6.06 mV. When red blood cells undergo shear stress in constricted vessels, they release ATP, which causes the vessel walls to relax and dilate so as to promote normal blood flow. When their hemoglobin molecules are deoxygenated, red blood cells release S-nitrosothiols, which also act to dilate blood vessels, thus directing more blood to areas of the body depleted of oxygen. Red blood cells can also synthesize nitric oxide enzymatically, using L-arginine as substrate, as do
Blood cell were first observed by Gabriel Andral, a French professor of medicine, and William Addison, a British physician, simultaneously. Both men believed that both red and white cells were altered in disease. With these discoveries, hematology, a new field of medicine, was established. Even though agents for staining tissues and cells were available, almost no advances were made in knowledge about the morphology of blood cells until 1879, when Paul Ehrlich published his technique for staining blood films and his method for differential blood cell counting Blood cell A blood cell, also called a hematopoietic cell, hemocyte, or hematocyte, is a