Effects of Ginkgo biloba extract(EGb 761) on the anti-pulmonary hypertensive action of enalapril were evaluated in rats. Pulmonary hypertension was induced by monocrotaline treatment (60mg/kg, I.p.) in normotensive rats. In the systolic pulmonary arte...
Effects of Ginkgo biloba extract(EGb 761) on the anti-pulmonary hypertensive action of enalapril were evaluated in rats. Pulmonary hypertension was induced by monocrotaline treatment (60mg/kg, I.p.) in normotensive rats. In the systolic pulmonary artery pressure, the control group was 33 +/- 2mmHg, comparing to the normal group of 19 +/- 1 mmHg. That of enalapril group(20mg/kg/day, p.o.) was 26 +/- 2 mmHg, and that of combined group of enalapril and Ginkgo biloba extract (EGb 761;60mg/kg/day, p.o.) was 20 +/- 2 mmHg. In the isolated lung preparation, acetylcholine, which was endothelium dependent vasodilator, induced the decrease of pulmonary artery perfusion pressure(-2.0 +/- 0.7mmHg) in normal group, but the increase of that of 3.4 +/- 0.6 and 3.0 +/- 0.9mmHg in control and enalapril group, respectively. And that of the combined group was -0.5 +/- 0.2mmHg. In the isolated pulmonary artery, acetylcholine(10-5M) induced the relaxation of 65 +/- 6% in normal group, but 15 and 8% in control and enalapril group, respectively. And that of the combined group was resulted 55 +/- 2%. These results suggested that co-administration of Ginkgo biloba extract(EGb 761) potentiated the anti-pulmonary hypertensive effects of enalapril through the increase of pulmonary vasodilation due to the protection of endothelial cell by antioxidant action of Ginkgo biloba extract (EGb 761).