In neonatal pulmonary hypertension, the blood vessels around newborn babies' lungs constrict, limiting the amount of oxygen getting into the blood. Researchers tried out a potential treatment for this life-threatening condition on newborn lambs.

What the researchers wanted to know: Does inhaled sodium nitrite counteract the effects of neonatal pulmonary hypertension?

What they did: The researchers experimented with newborn lambs, which were put under general anesthesia with either low-oxygen air or regular air, then inhaled a cloud of sodium nitrite. In another experiment, newborn lambs inhaled either nitrite or nitric oxide gas, which is the standard treatment for neonatal pulmonary hypertension.

What they found: Nitrite didn't start working quite as quickly as nitric oxide, and it didn't decrease pulmonary blood pressure by quite as much, but its effects lasted for more than an hour after the gas stopped. Nitric oxide's effects lasted only as long as the lambs were breathing it; after the gas stopped, their pulmonary blood pressure went back up within seconds. The various experiments also gave the scientists insight into how nitrite works on high blood pressure.

What the study means to you: Sodium nitrite might be a good way to treat neonatal pulmonary hypertension.

Caveats: Sheep aren't people, and clearly more research would be needed to find out if nitrite is safe and effective for human babies.

Find out more: About pulmonary hypertension in babies: kidshealth.org/parent/medical/lungs

Read the article: Hunter, C.J., et al. "Inhaled Nebulized Nitrite Is a Hypoxia-Sensitive NO-Dependent Selective Pulmonary Vasodilator." Nature Medicine. October 2004, Vol. 10, pp. 1122-1127.

Abstract online: www.nature.com