The postnatal changes in red blood cell NO levels.

Aim: To determine the levels of RBC HbSNO and HbFe(II)NO using chemiluminescence in very low birth weight infants breathing room air, during the first 2 days of life.

Method: RBC NO values were compared to the levels obtained in cord blood at birth from infants of similar gestational age. Five infants ranging from 25 to 27 weeks of gestation were sampled between 12 and 24 h after birth.

The effect of adult hemoglobin on red blood cell nitric oxide levels during fetal development.

Objective: To compare the levels of S-nitrosohemoglobin (HbSNO) at different gestational ages in newborn infants and correlate the levels of HbSNO with HbA and HbF.

Method: Cord blood samples of 22 newborn infants of different gestational ages (25-41 weeks) were analyzed. The levels of HbF and HbA were determined by HPLC and of HbSNO by chemiluminescence.

Developmental changes in NO bioavailability in fetal erythrocytes.

S-nitrosohemoglobin (HbSNO), where hemoglobin (Hb) is nitrosated at Cysbeta93, presumably controls delivery of the vasorelaxant nitric oxide (NO) to hypoxic tissues in an oxygen-sensitive manner. Little is known about how Hb regulates NO bioavailability during fetal development. A study was planned to determine the levels of HbSNO and HbFe(II)NO (NO bound to FeII of heme) in the cord blood of newborn infants of different gestational ages and establish their relationship with the levels of fetal Hb (HbF).