An animal model of hypertension seemed to confirm the finding that the more O-GlcNAc, the more blood vessels contract because these animals had higher O-GlcNAc levels. "Now we are trying to see why this is happening and what comes first. Is increased blood pressure leading to changed O-GlcNAc or are augmented levels of O-GlcNAc contributing to the change we see in the vasculature of hypertensives?" Dr. Tostes says. "If we know how this changes vascular function, we can understand some of the dysfunction that we see in diabetes."
To make sure they were targeting the O-GlcNAc sugar and not dealing with other effects of glucose on blood vessels, the researchers blocked the enzyme OGA, an enzyme that normally removes O-GlcNAc from proteins so they can revert to their normal state.
If the findings continue to hold true, drugs similar to those they use in the lab to inhibit OGA or OGT, the enzyme that adds O-GlcNAc to the protein, could one day help reduce the significant cardiovascular risk associated with diabetes, Mr. Lima says. "I think it looks very promising," Dr. Tostes adds.
Future studies will include blocking the pathway for adding O-GlcNAc in hypertensive animals to study the impact on blood pressure and vascular function.
|Contact: Toni Baker|
Medical College of Georgia