MANHATTAN -- Blocked or closed blood vessels mean a medical emergency: for instance, in heart attacks and strokes, time is of the essence.
Since the blood delivers the nutrients and removes the waste from all tissues, when a vessel is blocked, the tissues beyond the blockage are endangered. Doctors have to work to restore the blood flow quickly, usually within a few minutes or hours.
They can use several modern medical technologies: inflatable balloons within a vessel or "clot busting" drugs have made it a common occurrence to provide quick relief for blocked blood flow. But there is a downside to having these capabilities. In one of the ironies of medicine, tissue damage can also occur after blood flow is restored.
"Even with these modern technologies, a doctor is put between a rock and a hard place," says a Kansas State University scientist, a member of a research team whose investigations may one day help resolve the quandary.
"Eventually, a blockage will damage tissue, but using the new technologies to open the vessels and restore the blood flow to the tissues often places the doctor in the position of creating tissue damage, too," said Chris Ross. "That's because a very complex biochemical process that closely resembles inflammation happens after blood flow is restored."
In medical parlance, the blockage is ischemia; the process of blood flow restoration is reperfusion.
Ross and K-State physiologist Frank Blecha are studying this so-called reperfusion injury, a condition that's a major contributor to many important disease syndromes including coronary artery disease and stroke.
The Kansas State University researchers have discovered a substance, a very small protein called PR-39, that suppresses production of the toxic oxygen metabolites that contribute to the characteristic inflammation-like response of reperfusion injury.
Ross said the worrisome mechanisms of reperfusion injury could have evolved as
part of the body's response to i
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Contact: Frank Blecha
blecha@vet.ksu.edu
(785) 532-4537
Kansas State University
7-Jul-1998