During the mapping of the human genome conducted from 2000 to 2003, scientists discovered a protein called B-type natriuretic peptide (BNP) found to be helpful in diagnosing heart problems and in treating heart failure. There was just one catch: many cardiac patients experience low blood pressure, and unfortunately BNP lowered it even more.

Cardiology researchers from the Mayo Clinic have been able to overcome this limitation. They identified an alternative splicing (AS) of BNP in messenger RNA (produced by the same gene). By shortening the amino acid sequence of ASBNP for testing, they discovered that it delivered the same therapeutic benefits as BNP, but without lowering blood pressure. These include an increase in kidney filtration rate, suppression of harmful protein production, and the prevention of water and salt from flowing from the body. The goal is to eventually be able to give the drug intravenously to hospital inpatients.

"One of the biggest additional concerns for patients with heart failure is the health of their kidneys. Heart failure itself and some of the approaches used to treat it can have detrimental effects on the kidneys," says Mayo cardiologist and lead researcher Robert Simari, M.D. "The extreme case is that it can lead to the kidneys shutting down completely. Our hope is that this compound will help protect kidney function while patients are being treated, and possibly shorten their hospital stay and keep them out of the hospital."

The new peptide, which has been tested in the laboratory and in animal models, is expected to move into clinical trials in 2010. Findings have been published in the current issue of Proceedings of the National Academy of Scientists.

News Release: Mayo genomic discovery: Protecting kidney function during heart failure   www.mayoclinic.org   June 15, 2009