The aim of this study is to investigate the effects of nitric oxide, formed from L-arginine, on the production of endothelin?1 in vivo and in cultured endothelial cells. In mechanically ventilated anesthetized dogs (n...The aim of this study is to investigate the effects of nitric oxide, formed from L-arginine, on the production of endothelin?1 in vivo and in cultured endothelial cells. In mechanically ventilated anesthetized dogs (n = 5), mean pulmonary arterial pressure (PAPm) and pulmonary vascular resistance (PVR) during hypoxic ventilation (FIO2 = 0.10) was 25 ?3.1 kPa and 68.7 ?10.2 kPa.s / L respectively. IG-nitro-L-arginine methylester (L-NAME), an inhibitor of nitric oxide synthase, increased the peak value of PAPm and PVR during hypoxic ventilation to 36.6 ?4.7 kPa and 158.4 ?25 kPa.s / L and its effect lasted for 2-3 hours. Meanwhile, plasma endothelin? level in the femoral artery increased by 20.9+ 7.1, 25.6?7.7, 28.6?7.9 pg / ml at the 60 th, 120th, 180th minute after the injection of L-NAME respectively (P<0.05 vs hypoxic control before the injection). In cultured endothelial cells from umbilical veins, endothelin-1 level of culture medium in control group was 35.1 ?.9 pg / 105 cells /ml (n=9). L-NAME increased endothelin-1 level to 42.8 ?4.9pg / 105 cells / ml (n = 9, P < 0.05) in case of 10-11 mol / L and to 43.0+ 4.7 pg / 105 cells / ml in case of 10 -7 mol/L (n=9, F<0.05). These findings indicate that endogenous nitric oxide is an inhibitory modulator of hypoxic pulmonary vasoconstriction and that nitric oxide inhibits the production of endothelin? in vivo and in cultured vascular endothelial cells.展开更多
文摘The aim of this study is to investigate the effects of nitric oxide, formed from L-arginine, on the production of endothelin?1 in vivo and in cultured endothelial cells. In mechanically ventilated anesthetized dogs (n = 5), mean pulmonary arterial pressure (PAPm) and pulmonary vascular resistance (PVR) during hypoxic ventilation (FIO2 = 0.10) was 25 ?3.1 kPa and 68.7 ?10.2 kPa.s / L respectively. IG-nitro-L-arginine methylester (L-NAME), an inhibitor of nitric oxide synthase, increased the peak value of PAPm and PVR during hypoxic ventilation to 36.6 ?4.7 kPa and 158.4 ?25 kPa.s / L and its effect lasted for 2-3 hours. Meanwhile, plasma endothelin? level in the femoral artery increased by 20.9+ 7.1, 25.6?7.7, 28.6?7.9 pg / ml at the 60 th, 120th, 180th minute after the injection of L-NAME respectively (P<0.05 vs hypoxic control before the injection). In cultured endothelial cells from umbilical veins, endothelin-1 level of culture medium in control group was 35.1 ?.9 pg / 105 cells /ml (n=9). L-NAME increased endothelin-1 level to 42.8 ?4.9pg / 105 cells / ml (n = 9, P < 0.05) in case of 10-11 mol / L and to 43.0+ 4.7 pg / 105 cells / ml in case of 10 -7 mol/L (n=9, F<0.05). These findings indicate that endogenous nitric oxide is an inhibitory modulator of hypoxic pulmonary vasoconstriction and that nitric oxide inhibits the production of endothelin? in vivo and in cultured vascular endothelial cells.
