Rubidium and sodium transport across erythrocyte membrane: alterations due to a circulating factor

Essential hypertension patients can be divided into two groups on the basis of the presence or absence of a plasma factor able to inhibit rubidium uptake and sodium extrusion by the red blood cells. Nearly fifty percent of the patients studied present this factor. Preliminary results show that it is dialyzable, has a molecular weight around 500 daltons and cannot be extracted by chloroform.