NEW YORK: In a finding that has implications for the treatment of hypertension, researchers have identified what they believe is the "master switch" that regulates blood pressure.

The "master switch" is a mechanism by which a protein complex in the kidney controls the rise or fall of blood pressure, according to a paper published in the latest issue of the 'Journal of Clinical Investigation' .

Researchers at the Oregon Health and Science University liken the switch to a rheostat that modulates the balance of salt and potassium in the kidney, thereby raising or lowering blood pressure.

When the switch malfunctions, high blood pressure or hypertension occurs, the researchers suggest. Hypertension affects millions around the world and is a major cause of heart attacks, strokes and kidney failure. The root cause is unknown in 95% cases.

If the study's conclusions are borne out by further research, they can lead to better targeted and more effective drugs for the disease. Dr David H Ellison, who led the research team, likens the switch to a rheostat that modulates the balance of salt and potassium in the kidney, thereby raising or lowering blood pressure.

Writing about his team's findings, Ellison said that hypertension occurs when the switch malfunctions, as it does when certain mutations in the WNK kinase protein complex are present.

"It is not widely understood by the general public that hypertension is most often a kidney disease. If we can figure out the ways the kidney adjusts salt excretion, we can devise methods to prevent hypertension, cure it or design better treatments for it. Our findings in this study get us a step closer, we think," he said.

The researchers say that they have found out how a hormone called aldosterone, produced in the adrenal gland, can have different effects on sodium and potassium balance at different times.