Moscow, Mar 10 (PTI): Abnormally high blood pressure, or hypertension, may be caused by changes in brain activity and blood flow early in life, a new study has found.

In 90-95 per cent of people, high blood pressure has no identifiable cause, yet it is a risk factor for diseases of the brain, kidneys, heart, eyes and other parts of the body.

Although a lot is known about how blood pressure is regulated, its cause is still a mystery. Researchers from the Institute of Cytology and Genetics in Russia studied physiological changes in a rat model with inherited stress-induced arterial hypertension (ISIAH).

These rats develop high blood pressure at four to six weeks of age, and this is sustained throughout their lifetime.

The researchers compared the high blood pressure rats to a control group with normal blood pressure. As the high blood pressure group aged, the researchers observed changes in rates of blood flow in certain arteries.

They also noted changes in brain activity, specifically a decrease in the prefrontal cortex and an increase in the hypothalamus that did not occur in the group of rats with normal blood pressure.

This demonstrates a link between hypertension and changes in brain activity and blood flow. The researchers suggest that hypertension could be caused by these changes taking place early in life.

A clearer understanding of this process could help us prevent this condition. "The study of early physiological changes in ISIAH rats may help clarify the cause of high blood pressure. Understanding this could help us prevent the disease early on," said Alisa Seryapina, from Institute of Cytology and Genetics.

The study was published in the journal Experimental Physiology.