They'll mimic the way many people work an hour of stress, a few minutes of relief, then back to stress by getting the young people to play competitive video games, then measuring how gene blockers affect sodium excretion. "Ultimately, you want to know how to treat people with this variation," Dr. Harshfield says. "There is still a need to figure out why some people respond to some therapies and other don't," adds Dr. Pollock. "That is not our specific question but these studies will help address that. We have to identify what is it about different individuals that make them react more to stress, makes them retain more salt."
Obesity, which is associated with increased blood pressure reactivity, is probably a differentiator, Dr. Pollock says. Fat cells actually secrete angiotensin, which gets into the bloodstream. "We are arguing in our study that you might want to treat patients differently depending on whether or not they are obese. The angiotensin receptor blocker may be more effective in obese individuals who have angiotensin falling out into their bloodstream," says Dr. Harshfield. Consequently they'll also compare the effectiveness of the blocker in obese and normal-weight individuals with impaired sodium excretion.
Another project is exploring the role of oxidative stress, or reactive oxygen species, in raising blood pressure. In an animal model genetically predisposed to salt-sensitive hypertension, Dr. Jennifer Pollock, biochemist in MCG's Vascular Biology Center and a program project leader, has shown a prolonged recovery to normal blood pressure following stress. She's also found oxidative stress levels go up with stress. Oxidative stress, or reactive oxygen species, helps make normal chemical reactions in the body but, in excess, can cause havoc. In fact, when she gives the rats an antioxidant before a stressor, blood pressure doesn't rise as high and recovery is mo
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| Contact: Toni Baker tbaker@mcg.edu 706-721-4421 Medical College of Georgia Source:Eurekalert |