• Neutrophil;
  • nitric oxide;
  • pregnancy;
  • superoxide anion

Problem  Oxygen radical formation by neutrophils during pregnancy is not well studied.

Method of study  We studied neutrophil-derived superoxide anion (Oinline image) and nitric oxide (NO) values in 75 normal pregnant women, 12 postpartum women, and 10 non-pregnant women. Oinline image production was measured by the superoxide dismutase-inhibitable reduction of ferricytochrome c. NO production was measured by accumulation of the stable end product nitrite using a modified Griess reaction method.

Results  Oinline image production of neutrophils stimulated by chemotactic peptide was significantly enhanced in the early second trimester of pregnancy. l-arginine analogue-inhibitable nitrite production was induced in neutrophils from pregnant women, but not from postpartum and non-pregnant subjects. In third-trimester subjects but not non-pregnant subjects, neutrophils pre-treated with l-arginine analogues enhanced Oinline image production compared with untreated neutrophils.

Conclusion  These findings indicate that Oinline image and NO production by neutrophils during pregnancy were modulated separately, whereas neutrophil-derived NO might function as a regulator of Oinline image.