|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1997 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1996 : ¥1,100,000 (Direct Cost : ¥1,100,000)
1.Establishment of a animal moldel of persistent pulmonary hypertension of the newborn In 15 newborn piglets, pulmonary artery pressure was continuously measured by the catheter which was inserted from the internal jugular vein. At this condition, low concentration oxygen (FiO2<15%) was administer to increase the pulmonary pressure. In the condition under the hypooxgenation and hypercapnia, pulmonary arterial pressure of newborn piglet within 48 hours after birth was almost equal to systemic arterial pressure, and right to left shunt was present. Most of all animal model died within 7 days under this condition (FiO2<15%) due to decreasing of systemic arterial pressure. On the other hand, in 4 newborn piglets who were administered indometacin in the uterus, pulmonary artery pressure was within 60% of systemic arterial pressure.
2.Evaluation of pulmonary vascular response for inhaled nitric oxide in patients with pulmonary hypertension Low dosage nitric oxide (5-10ppm) was inhaled in pati
ents with congenital heart disease complicated with pulmonary hypertension, and the change of pulmonary vascular resistance was measured. Such effectiveness was compared to that of high concentration oxygen. Additionally, the effectiveness of nitric oxide under the different degree of pulmonary hypertension was investigated. In severe pulmonary hypertension such as Eisenmenger syndrome, both high concentration oxygen and the normal oxygen with nitric oxide showed no affect on the hemodynamical variables. In patients moderate pulmonary hypertension, pulmonary artery pressure and pulmonary vascular resistance both significantly decreased with high oxygen and with the nitric oxide inhalation, but these decreases were not found in patients with normal pulmonary pressure. Our data suggested that inhaled nitric oxide, even in a low dosage, was a potent and selective pulmonary vasodilator in patients with congenital heart disease complicated with pulmonary hypertension.