Red blood cell (erythrocyte) (RBC)

Red blood cells (erythrocytes) are specialized, anucleate cells responsible for transporting oxygen from the lungs to body tissues and facilitating carbon dioxide removal back to the lungs. Their primary functional component is hemoglobin, a metalloprotein that binds oxygen reversibly at high concentrations in the lung and releases it in peripheral tissues where it is needed for cellular respiration. The biconcave shape and flexible membrane allow them to traverse narrow capillaries efficiently. In addition to their classical role in gas exchange, red blood cells also participate in regulating vascular tone by releasing vasodilatory molecules such as nitric oxide and ATP under hypoxic conditions, thereby matching local tissue perfusion with metabolic demand. Increasing the number of circulating erythrocytes—through endogenous mechanisms like elevated erythropoietin secretion during hypoxia or exogenous interventions—raises total oxygen-carrying capacity but carries risks if not properly regulated.[1][2][3][4][5][6]

Other names

Erythrocytered cellRBCred corpuscle

For drugs increasing circulating erythrocytes: - Stimulate bone marrow production of red blood cells by mimicking or enhancing endogenous erythropoietin activity[3]. - Supplement iron for hemoglobin synthesis. - Direct transfusion increases circulating RBC mass.