167: Intrauterine growth restriction increases nitric oxide synthase activity in the lungs of female but not male rats at birth

Abstract

Intrauterine growth restriction (IUGR) increases the incidence of pulmonary hypertension (PH) in newborns and adults. Both forms of PH are associated with decreased nitric oxide synthase (NOS) activity. Normal vascular growth requires NOS activity at critical periods during development. Abnormal pulmonary vascular growth may predispose IUGR offspring to PH. We have shown that IUGR male rats develop right ventricular hypertrophy, a marker of elevated pulmonary vascular pressures, as adults. Whether IUGR alters age- and gender-specific levels of the endothelial (eNOS) and inducible (iNOS) NOS isoforms and total NOS activity in IUGR rat lungs is not known.