New kidney discovery may help heart

The kidneys filter waste and excess water from the body and keep sodium and other electrolytes in balance, but they also secrete crucial protein hormones that regulate heart function and the production of red blood cells.

Eight million Americans suffer from kidney impairment, some 500,000 of whom have end-stage renal disease (ESRD), for which dialysis is a lifesaving treatment. Dialysis paired with dietary restrictions can substitute for the kidney’s filtering and electrolyte-balancing roles, but even with medications that replace important hormones ESRD patients are prone to serious, sometimes fatal, heart problems.

Gary V. Desir, M.D., professor of medicine, and research scientist Jianchao Xu, M.D., Ph.D., suspected that there might be additional kidney hormones that promote cardiac health. In May, the scientists announced in The Journal of Clinical Investigation that they had discovered a new kidney protein, renalase, that lowers blood pressure and improves heart function.

Xu says the discovery “has immediate implications for therapy.” Desir agrees: “We are hopeful that renalase will impact the treatment of chronic kidney disease and change the way in which we treat patients with chest pain and heart attacks.”