New model shows gender differences in high blood pressure, Jefferson scien...( es which are sympathetic system neurot...),Health

Dr. Eckhart and her co-workers don't think that GRK5 is necessarily the sole cause of hypertension. But because it is correlated with some types, they wanted to look at the molecular mechanisms and try to get a better idea of its role. They created mice that overexpressed GRK5 in the vascular smooth muscle, hoping to "begin seeing what receptors and signaling pathways might be involved in hypertension with elevated GRK5 levels." What they found surprised them.

"There are not too many molecules shown in mice to raise basal blood pressure straight up," she says. "The effect is quite profound. There are a lot of checks and balances that keep the pressure down. We were surprised there was such an increase at resting. We might have thought this would happen if we stressed the animal, but we saw it at baseline. Obviously it is affecting receptors important in the resting state."

When they looked more closely, they found that increases in blood pressure differed according to sex.

"Ultimately, we'd like to see if GRK5 is a biomarker, a predictor for a multifactorial disease like high blood pressure," she says. "Developing a good therapeutic profile for such patients might helps us prescribe the correct drugs more quickly. We hope the work might lead to better, more specific ways to treat high blood pressure than currently used diuretics and specific receptor blockers." She notes that even though these mice have hypertension, their blood vessels are not enlarged, which is typical of progressive heart failure and kidney disease and are associated with high blood pressure. "These mice didn't have these associated cardiovascular risks," she says. "Maybe the GRK5 is somehow protective of other organs, despite its role in causing hypertension.

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5-Oct-2005