Effects of hyperoxia and nitric oxide on endogenous nitric oxide production in polymorphonuclear leukocytes.

Background: Exposure to hyperoxia and nitric oxide (NO) occur frequently during the treatment of neonatal hypoxic pulmonary failure.

Objective: The aim of the study was to quantify the endogenous synthesis of NO in neonatal polymorphonuclear neutrophils following exposure to hyperoxia and NO in vitro.

Methods: Neonatal cord blood was exposed to room air, 25, 30 and 100% oxygen and 10 or 20 ppm NO added to the different oxygen concentrations for up to 30 min.