Researchers explore new blood pressure treatment technique

The researchers kept blood pressure from worsening and nearly eliminated kidney damage in rats exposed to cold weather, which can constrict blood vessels and overload the kidneys with hormones, according to findings published in the journal Gene Therapy.

Using a corrective gene, scientists were able to block a protein in the kidneys that triggers high blood pressure and kidney damage. The protein, called a mineralocorticoid receptor, signals the body to absorb sodium and water into the bloodstream. This increases the amount of blood in the body, also increasing blood pressure. While some treatments already on the market block the MR protein, the medications don’t target it specifically, interfering with other receptors and causing unwanted side effects.

“This new technique can specifically and efficiently inhibit the protein and prevent the progression of hypertension,” said Dr Zhongjie Sun, a University of Florida assistant professor of medicine, physiology and functional genomics and the lead author of the study. “I’m very optimistic this gene complex will be used for human gene therapy to treat hypertension.”

To block the protein, researchers used a technique called RNA interference. A harmless virus ferries fragments of RNA into the body, where they infiltrate cells and stop the protein. This represents the first time scientists have used the approach to treat hypertension and kidney damage.

The treatment kept blood pressure from escalating but did not lower it to normal levels, most likely because the researchers monitored the rats only for three weeks after they were treated. Blood pressure continued to rise in rats that did not receive the therapy.

The researchers plan to study what happens to the rats when they are observed for a longer period of time after therapy, which Dr Sun suspects will give their blood pressure more time to drop. It would be unhealthy for blood pressure to drop rapidly, in rats or humans, Dr Sun added.

While researchers expected the treatment to prevent hypertension, they were surprised to discover that it dramatically reduced damage to the kidneys as well. It was already known that hypertension can lead to kidney dysfunction, particularly in the later stages of the disease, but these findings show that the MR protein may play more of a role in causing kidney damage than researchers previously understood.

More tests are needed to determine if gene therapy for hypertension will work in humans, but Dr Sun said he is hopeful this research is the first step toward a long-term way to treat both high blood pressure and kidney damage.