金沙游戏官网:Secrets of a stealthy killer

 作者:花胁绡     |      日期:2019-02-26 02:07:00
EXPOSURE to carbon monoxide over long periods may damage the nervous system by raising levels of nitric oxide in the blood, say researchers in the US. High doses of carbon monoxide (CO) can kill in minutes. The gas binds to the blood pigment haemoglobin and displaces oxygen, with the result that cells suffocate. But nobody has been able to explain the neurological symptoms linked to long-term, low-level CO exposure from sources such as poorly ventilated gas heaters. Now scientists at the University of Pennsylvania in Philadelphia have found that CO also displaces nitric oxide from another part of the haemoglobin molecule, releasing the gas into the blood (Chemical Research in Toxicology, vol 10, p 1023). High nitric oxide levels are thought to damage brain cells and blood vessels. “Hopefully this will lead to a greater sensitivity to the need to be more aggressive about prevention and treatment,