健康英语新闻:Canadian researchers discover new enzyme function for anemia

WASHINGTON, Oct. 3 (Xinhua) -- Researchers at St. Michael's Hospital in Canada have discovered a new function for an enzyme that may protect against organ injury and death from anemia, according to a study appearing Monday in the U.S. journal of the Proceeding of the National Academy of Sciences.

Researchers found that when people have anemia, neuronal nitric oxide synthase (nNOS) -- an enzyme in nerve cells that produces nitric oxide, an important signaling molecule in the body -- increases the body's ability to respond, adapt to low oxygen levels and makes the body more efficient in delivering oxygen to tissues. They also found that levels of nNOS in the brain increased in anemic mice, and that the mice without this enzyme die earlier, and with higher hemoglobin levels.

"Identifying this mechanism may lead to new therapies and approaches to improving outcomes for anemic patients," said Dr. Greg Hare, a researcher at the Li Ka Shing Knowledge Institute of the hospital and one of the lead investigators of the study.

Anemia occurs when blood has a lower than normal number of red blood cells or hemoglobin -- an iron-rich protein that carries oxygen from the lungs and heart to the rest of the body. Cells need oxygen to survive and to produce energy for all bodily functions. The condition has many different causes including infection (malaria, HIV, parasites), nutritional deficiencies (iron, folate, B12), genetic mutations, pregnancy, trauma and surgical blood loss.

"This research will help us identify when an anemic patient is at greatest risk for injury and death when undergoing surgery," said Hare. "Research is underway to test these findings in humans."