A common anti-angina drug could help protect the heart against the effects of carbon monoxide poisoning.
Researchers from the University of Leeds examined the effect of ranolazine in single cardiac cells to learn why carbon monoxide triggers arrhythmias – an irregular or abnormally paced heartbeat. The drug targets a sodium channel in the heart – the same channel that can also induce irregular heartbeats.
Exposure to the gas caused a key membrane channel carrying sodium ions through the heart to stay open for longer, causing calcium build up in the heart and altering the heart’s regular cycle.
Ranolazine was then trialled on rats exposed to carbon monoxide by researchers at Université Montpellier 1 and Université de Avignon in France. Researchers testing the drug’s protective effects discovered the drug markedly reduced the chance of arrhythmia in the animals.
“At the molecular level, we have shown that the mechanism underlying this adverse effect of carbon monoxide is a rise in the level of nitric oxide within cells, which in turn alters the function of the sodium channel,” said Professor Derek Steele, from Leeds.
The findings could have important implications for the development of a protective treatment for adults and children exposed to toxic levels of the gas, and to those whose daily work involves exposure to lower levels of the gas, like fire fighters.
“When patients are admitted to hospital with carbon monoxide poisoning, the main problem doctors face is preventing damage to the body whilst the body slowly removes the chemical,” said Professor Chris Peers, who led the research published in American Journal of Respiratory and Critical Care Medicine. “We’ve shown that ranolazine can rapidly protect the heart and prevent the kind of cardiac events which threaten patients long after their exposure to the gas.”
The next stage of the research is to replicate these findings in human trials.