Meat additive may help blood flow
Published September 6, 2005
WASHINGTON - Could the salt that preserves hot dogs also preserve your health?
Scientists at the National Institutes of Health think so. They've begun infusing sodium nitrite into volunteers in hopes that it could prove a cheap but potent treatment for sickle cell anemia, heart attacks, brain aneurysms, even an illness that suffocates babies.
Those ailments have something in common: They hinge on problems with low oxygen, problems the government's research suggests nitrite can ease.
Beyond repairing the reputation of this often maligned meat preservative, the work promises to rewrite scientific dogma about how blood flows and how the body tries to protect itself when that flow is blocked. Indeed, nitrite seems to guard tissues - in the heart, the lungs, the brain - against cellular death when they become starved of oxygen.
It doesn't mean artery-clogging hot dogs are healthy.
But the NIH researchers have filed for new patents on this old, overlooked chemical and are hunting a major pharmaceutical company to help develop it as a therapy - even as doctors await the enrollment of sick patients into research studies in coming months. The scientists are so convinced of nitrite's promise that lead researcher Dr. Mark T. Gladwin says the government will pursue drug development on its own if necessary.
"We are turning organs into hot dogs," Gladwin jokes. Then he turns serious: "We think we stumbled into an innate protection mechanism."
If it works, "this drug would be pennies to dollars per day," says Dr. Christian Hunter of California's Loma Linda University. By January, Hunter hopes to begin studies of nitrite treatment for babies with an often fatal disease called pulmonary hypertension. "It's so easy to use."
Gladwin and an NIH cardiologist, Dr. Richard Cannon III, discovered nitrite's effect by accident while studying a related compound, nitric oxide, long known to improve blood flow by dilating blood vessels, but difficult to use as a drug.
Gladwin and Cannon injected sodium nitrite into healthy volunteers. Tiny doses almost tripled blood flow. Moreover, when people exercised, nitrite levels plummeted in the muscles being worked - the body was using it.
The researchers were stunned. For 100 years, scientists thought nitrite had little medical relevance.
High doses are an antidote for cyanide poisoning, but they're also toxic. The low levels that naturally occur in the human body were thought to be inert, unimportant. Not anymore.
"This has led to an avalanche of work," says Gladwin, who this week hosts an NIH meeting where scientists will compare nitrite research.
The work done so far is "sufficiently encouraging to warrant a full-court press," says Dr. Franklin Bunn, a Harvard Medical School professor who has reviewed much of the research.
At NIH's hospital in Bethesda, Md., Gladwin has infused nitrite into six sickle-cell patients. This first-stage study is designed to test safety, not nitrite's effect on pain, but it is dilating participants' blood vessels, he says.
[Last modified September 6, 2005, 03:15:21]
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