New class of molecules may help prevent fatal complication in patients with kidney disease

Researchers at the University of Maryland School of Medicine have made an important discovery about why potassium builds up to dangerous levels in the bloodstream, a relatively common medical problem that affects about eight percent of hospitalized patients. They have identified a new molecular pathway and a new class of molecules responsible for preventing potassium from being excreted normally through the kidney. Their study was just published in the Journal of Clinical Investigation.

The researchers hope that their discovery will lead to the development of a new class of drugs to treat the condition, known as hyperkalemia, which is caused when patients can't properly excrete excess potassium. If it is not treated promptly, it can cause fatal cardiac arrest.

"We are particularly excited about the translational potential of our basic science discovery," says Paul A. Welling, M.D. professor of physiology at the University of Maryland School of Medicine. "Currently, there are no drugs that specifically target the molecular defect in kidney potassium retention. This new class of drugs will pave the way to allow damaged kidneys from long-standing high blood pressure, diabetes or heart disease, to continue to properly excrete potassium in the urine, so that potentially fatal hyperkalemia can be prevented."

Potassium is critical for proper functioning of muscles, nerves and the heart. The kidney is the organ primarily responsible for eliminating excess potassium if too much of it accumulates in the blood stream. People at highest risk for abnormally high levels of potassium in the blood are those with kidney disease because they cannot properly excrete the potassium through the urine. About 67 percent of cases of severe hyperkalemia are fatal if they are not caught and treated promptly.