Lack of Iron-Regulating Protein Causes Polycythemia and Pulmonary Hypertension.

A lack of iron regulatory protein 1 (Irp1) caused pulmonary hypertension and polycythemia (excess red blood cell production) in a recentCell Metabolism study in mice. Animals lacking Irp1 produced high levels of hypoxia inducible factor 2-alpha (HIF2 alpha), a protein produced in response to low oxygen conditions, which in turn spurred production of erythropoietin to stimulate red blood cell production. A low-iron diet worsened polycythemia in the animals. The findings suggest that changes in the gene for Irp1 may play a role in human cases of polycythemia and high blood pressure in the lungs.