The changes of nitric oxide synthase in placenta during fetal cardiac bypass / 中华胸心血管外科杂志

ABSTRACT

Objective To study the changes of nitric oxide synthase in placenta during fetal cardiac bypass. Methods Eight pregnant ewes (gestation 120～140 d)were divided equally into control group and bypass group. Bypass group underwent fetal cardiac bypass with centrifugal pump and placenta. Fetal hemodynamic date and blood gas value were recorded before and after bypass. Placenta vascular resistance was calculated. Fetal serum nitric oxide (NO), serum endothlin-1(ET-1) and nitric oxide synthase (NOS) of placenta tissue were assayed. Transcriptions of endothelial NOSmRNA in placental tissue were assayed with RT-PCR technique. Results Acidosis and pressure of oxygen decreased after bypass appeared in fetal lamb of bypass group. Placenta vascular resistance of bypass group elevated significantly (P