Researchers at Yale School of Medicine and the VA Connecticut Healthcare System in West Haven identified a novel human kidney protein called renalase that regulates both heart contraction and blood pressure; it is a strong candidate for easily administered treatment of advanced kidney and cardiovascular disease.
Over eight million people in the U.S. have kidney impairment and 500,000 have end-stage kidney disease (ESRD), for which treatment is often limited to dialysis. Elevated blood pressure and cardiovascular disease are commonly associated problems.
Renalase is secreted by the kidneys and circulates freely in the bloodstream. Patients with kidney disease have very low levels of renalase, suggesting that its absence may lead to the cardiovascular complications found in ESRD.
“This is one of the most exciting findings of kidney metabolism in recent years,” said Jianchao Xu, M.D., associate research scientist, attending physician and lead author. “It has immediate implications for therapy.” Like erythropoietin the human renalase protein could be injected to replace what is lost in kidney disease.
While the kidneys remove waste and extra water from the body and control the balance of certain chemicals in the blood like sodium, phosphorus and potassium, they also have another function. They secrete hormones, like rennin and erythropoietin, into the bloodstream to regulate blood pressure and red blood cell production.