THURSDAY, July 6, 2006 (HealthDay News) -- Mice infected with the agent of scrapie -- a brain-wasting disease of sheep -- suffered heart damage and had high levels of the scrapie agent in their heart about two years after they were infected in the brain, a new U.S. study finds.
The finding suggests that heart infection may be a previously unrecognized aspect of scrapie. The study may also lead to a better understanding of an illness in humans called human amyloid heart disease.
"Although much work remains to be done, the diseased hearts seen in the mouse study have similarities to human amyloid heart disease," Dr. Anthony S. Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases (NIAID), said in a prepared statement. NIAID scientists collaborated in the study.
Scrapie belongs to a family of prion (misfolded proteins) diseases that include Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy or "mad cow" disease in cattle, and chronic wasting disease in deer and elk.
As reported Thursday in the online edition of the journal Science, the new findings provide cardiologists with an animal model in which to study amyloidosis, a form of human heart disease characterized by waxy protein deposits that stiffen the heart, reduce its pumping ability, and lead to fatal heart stoppage.
"Although several types of protein are known to form heart amyloid, this is the first time prion protein amyloid has been found in heart muscle and also found to cause heart malfunction. That's exciting for cardiologists, because this study connects the two fields of research," Dr. Bruce Chesebro, a senior author of the study and a virologist at the NIAID's Rocky Mountain Laboratories, said in a prepared statement.
The U.S. National Library of Medicine has more about prion diseases.