pigs and heart and gene theapry
- NEW YORK (Reuters Health) - A gene therapy technique has been shown to steady irregular heartbeat in pigs, according to a report. The researchers hope that one day the technique may help humans with arrhythmia, an irregular heartbeat that in severe cases can lead to cardiac arrest unless treated with medication, implanted pacemakers or defibrillators.
"We have basically proven that it is possible to use gene therapy to help heart arrhythmias, but this is only the beginning. A lot more research will be required if this type of gene therapy is to cross over into humans," lead author Dr. J. Kevin Donahue told Reuters Health.
In the December issue of Nature Medicine, Donahue and colleagues report that they used a genetically modified adenovirus--a harmless virus often used in gene therapy--to treat five pigs.
The virus contained a gene capable of making the inhibitory G protein, which is active in the atrioventricular node, a spot of tissue found in the heart that helps control heartbeat.
The researchers snaked a catheter into an artery close to the node and released the genetically modified virus. A second group of pigs (the "control" group) was given a virus with a gene unrelated to heart function.
After a week, the scientists measured electrical impulse rates and confirmed that the gene was taken up in the cells in the pigs' hearts. In addition, the investigators induced a type of severe heartbeat irregularity in the pigs and found that those that had received the G protein had a 20% decrease in heart rate compared with the control group of pigs, Donahue explained.
While drug treatment can have the same effect, such medications may cause side effects, Donahue said. Severe heart arrhythmias can also be treated with a pacemaker or defibrillator implanted in the body, but these may increase the risk of infection.
Gene therapy, on the other hand, would be targeted to just one specific part of the body, Donahue pointed out. He suggested that such a therapy might be available for humans in about 5 years.
SOURCE: Nature Medicine 2000;6:1395-1398.
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