U. IOWA (US)—A protein channel helps nerve sensors in blood vessels keep blood pressure in check, new research shows. Without the protein channel, known as ASIC2, the sensors are unable to send the brain the signals it needs to properly control blood pressure.
The finding, which was based in animal models, is important because it could be used to create new treatments to prevent high blood pressure (hypertension). The results of the study by researchers at the University of Iowa appear in the Dec. 24 print issue of the journal Neuron.
“Sensors in your body’s blood vessels sense when your blood pressure goes up, for instance, when you get mad at someone,” says the study’s principal investigator Frank Abboud, professor of internal medicine and molecular physiology and biophysics and director of the Cardiovascular Research Center at the University of Iowa. “These built-in sensors perceive the change and trigger a nearly instantaneous adjustment by sending signals to the brain, which in turn tells the blood vessels how to adjust.
“By knowing more about what makes these sensors—known as baroreceptors—malfunction, we may be able to find ways to make them work properly and prevent high blood pressure,” adds Abboud, who also holds the Edith King Pearson Chair in Cardiovascular Research.
In the current study, the team showed that the ASIC2 channel was present in the nerve cells of mice blood vessels and that when the channel was defective, the nerve activity was also defective. They also created a mouse model that did not have the gene that codes for the protein channel and thus had no ASIC2 channels. These mice without ASIC2 channels had high blood pressure. The channels play a key role in the electrical activity that is needed to control blood pressure.
“The ASIC2 channel allows a current to be generated at the nerve endings in blood vessels,” he says. “However, when there is no ASIC2, those nerve endings become defective and cannot produce electrical current, and the nervous system loses the ability to get the blood vessels to dilate when necessary. As a result, the vessels remain constricted and the blood pressure stays high even when it should not.”
The study was supported by grants from the National Institutes of Health, a VA Merit Review Award from the Department of Veterans Affairs, and Heartland Affiliate Postdoctoral Fellowships from the American Heart Association.
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