A breakthrough therapy shows promise in the fight against a deadly heart disease that strikes both dogs and people, Canadian researchers report.
In the current issue of the American Journal of Physiology, scientists from the University of Guelph found that a naturally-occurring molecule called dAPT (2-Deoxyadenosine triphosphate) restored normal function in cardiac muscle cells taken from dogs with dilated cardiomyopathy (DCM).
The molecule plays a role in heart-muscle contraction.
Lead researcher Lynne O'Sullivan, of the Ontario Veterinary College (OVC), says this study suggests that dAPT is a "promising therapeutic approach worth further investigating for the treatment of DCM." The next step would be to create a gene therapy technique to deliver the molecule in patients. The scientists also identified abnormalities in heart-muscle tissues from dogs affected with DCM.
In dogs, DCM is one of the leading causes of heart failure—also known as congestive heart failure (CHF)—in which the heart muscle becomes so weak it can no longer deliver adequate blood and oxygen to support all of a body's organs. Its cause is unknown, but genetics appears to play a part in its development. According to the Doberman Pinscher Club of America, about 30 percent or more of DCM in humans is familial and it is likely that that figure is the same in the breed.
O'Sullivan, one of 10 board-certified veterinary cardiologists in Canada, runs the OVC's Doberman DCM screening program. Other large-breed dogs also show relatively high rates of this heart abnormality. It usually appears in middle-aged or senior dogs.
In DCM, the muscles in the heart's main pumping chamber become stretched out and thin, impairing the organ's function. It is characterized by an enlarged and weakened heart. The progressive loss of cardiac function is generally not detected until the patient is showing symptoms, such as coughing, weakness, fainting and difficulty breathing or exercising.
The experiment was conducted on dogs, but it has major implications for human heart patients, as well.
“The cardiovascular systems of dogs and people are very similar,” said Glen Pyle in a statement from the university. Pyle is a professor in OVC’s Department of Biomedical Sciences and a member of U of G’s Centre for Cardiovascular Investigations. The scientists are working with researchers from Finland and the University of Washington to further explore the therapy.
According to the Centers for Disease Control and Prevention (CDC), more than 5 million Americans suffer from the condition. About half of people who develop CHF will die within five years of diagnosis. Other recent studies have shown potential for dATP in humans.
The scientists describe their findings in this clip from CTV News:
Header image: Lynne O’Sullivan (back to camera) and Glen Pyle conduct a cardiology exam on Roxy. Also pictured are vet tech Heidi Chambers and owner Phyllis Markle. Credit: Karen Mantel