The effects of 3,4-DHAP on hypoxic pulmonary and systemic vascular responses were studied in anaesthetized dogs. The percentage change in pulmonary vascular resistance(△PVR%)and that in systemic vascular resistance(...The effects of 3,4-DHAP on hypoxic pulmonary and systemic vascular responses were studied in anaesthetized dogs. The percentage change in pulmonary vascular resistance(△PVR%)and that in systemic vascular resistance(△SVR%)induced by 5 min hypoxia decreased significantly.3,4-DHAP in doses of 1 mg/kg,3mg/kg,and 10 mg/kg i.v caused a decrease in b PVR% from the control value of 47.27±22.27% to 24.62±21.76%,18.15±18.73%,and 24.10±19.76% respectively, and a decrease in △SVR% from the control value of 12.91±7.39% to -0.34±12.7%,-2.11±12.76%,and -2.37±15.52% respectively.The results showed that 3,4-DHAP could decrease the hypoxic responses of pulmonary and systemic blood vessels.But it did not change △PVR% or △SVR% in dose of 30mg/kg,neither did it influence the heart rate,cardiac output or cerebral blood flow during hypoxia in all the doses used.展开更多
The roles of sympathicus, sensory neuropeptides (SNP),cyclooxygenase metabolites (COX-M), lipoxygenase metabolites (LOX-M), endothelium derived relaxing factor (EDRF),reactive oxygen (ROS) and potassium channels (PC) ...The roles of sympathicus, sensory neuropeptides (SNP),cyclooxygenase metabolites (COX-M), lipoxygenase metabolites (LOX-M), endothelium derived relaxing factor (EDRF),reactive oxygen (ROS) and potassium channels (PC) in the hypoxic pulmonary vasoconstriction (HPV) and hypoxic cerebral vasodilation (HCVD) were investigated in intact rats, rabbits and dogs. The results showed that during hypoxia,the excitation of sympathicus caused a constriction of both pulmonary and cerebral vessels,while SNP, EDRF and the opening of voltage sensitive PC caused the dilation of both of them; LOX-M mediated HPV and HCVD, COX-M might serve as their modulators; the blockade of ATP sensitive PC induced by hypoxia mediated HPV, but had no effect on HCVD; the reduction of O_2￣- in the lung might potentiate HPV, however, O_2￣- remained unchanged in brain during hypoxia. It is suggested that the alterations of LOX-M,ROS and the ATP sensitive PC are the factors accounting for the difference in the response of pulmonary and cerebral vessels to hypoxia.展开更多
To investigate the effects of prostaglandins (PGs) and leukotrienes (LTs) on hypoxic pulmonary vasoconstriction (HPV), in vivo rats experiment and in vitro perfused lung experiment were conducted. The effect o...To investigate the effects of prostaglandins (PGs) and leukotrienes (LTs) on hypoxic pulmonary vasoconstriction (HPV), in vivo rats experiment and in vitro perfused lung experiment were conducted. The effect of hypoxia on hemodynamics, concentrations of TXB 2 and 6 keto PGF 1α in serum and lung tissue during hypoxia and effects of PGs and LTs on HPV were observed. The results showed that pulmonary arterial pressure (P pa ) and pulmonary vascular resistance were increased during hypoxia, but cardiac output and systemic arterial pressure were decreased. There were increases of the concentrations of TXB 2 and 6 keto PGF 1α and their ratio in serum and lung tissue during hypoxia. After use of cyclooxygenase inhibitor (indomethacin) in vivo and in vitro , HPV was augmented respectively, but after use of lipoxygenase inhibitor (diethylcorbamazine) or leukotriene receptor blocker (LY 171883), HPV was attenuated. It was suggested that LTs mediated pulmonary vasoconstriction, PGs inhibited pulmonary vasoconstriction and they played a modulating role during hypoxia.展开更多
文摘The effects of 3,4-DHAP on hypoxic pulmonary and systemic vascular responses were studied in anaesthetized dogs. The percentage change in pulmonary vascular resistance(△PVR%)and that in systemic vascular resistance(△SVR%)induced by 5 min hypoxia decreased significantly.3,4-DHAP in doses of 1 mg/kg,3mg/kg,and 10 mg/kg i.v caused a decrease in b PVR% from the control value of 47.27±22.27% to 24.62±21.76%,18.15±18.73%,and 24.10±19.76% respectively, and a decrease in △SVR% from the control value of 12.91±7.39% to -0.34±12.7%,-2.11±12.76%,and -2.37±15.52% respectively.The results showed that 3,4-DHAP could decrease the hypoxic responses of pulmonary and systemic blood vessels.But it did not change △PVR% or △SVR% in dose of 30mg/kg,neither did it influence the heart rate,cardiac output or cerebral blood flow during hypoxia in all the doses used.
文摘The roles of sympathicus, sensory neuropeptides (SNP),cyclooxygenase metabolites (COX-M), lipoxygenase metabolites (LOX-M), endothelium derived relaxing factor (EDRF),reactive oxygen (ROS) and potassium channels (PC) in the hypoxic pulmonary vasoconstriction (HPV) and hypoxic cerebral vasodilation (HCVD) were investigated in intact rats, rabbits and dogs. The results showed that during hypoxia,the excitation of sympathicus caused a constriction of both pulmonary and cerebral vessels,while SNP, EDRF and the opening of voltage sensitive PC caused the dilation of both of them; LOX-M mediated HPV and HCVD, COX-M might serve as their modulators; the blockade of ATP sensitive PC induced by hypoxia mediated HPV, but had no effect on HCVD; the reduction of O_2￣- in the lung might potentiate HPV, however, O_2￣- remained unchanged in brain during hypoxia. It is suggested that the alterations of LOX-M,ROS and the ATP sensitive PC are the factors accounting for the difference in the response of pulmonary and cerebral vessels to hypoxia.
文摘To investigate the effects of prostaglandins (PGs) and leukotrienes (LTs) on hypoxic pulmonary vasoconstriction (HPV), in vivo rats experiment and in vitro perfused lung experiment were conducted. The effect of hypoxia on hemodynamics, concentrations of TXB 2 and 6 keto PGF 1α in serum and lung tissue during hypoxia and effects of PGs and LTs on HPV were observed. The results showed that pulmonary arterial pressure (P pa ) and pulmonary vascular resistance were increased during hypoxia, but cardiac output and systemic arterial pressure were decreased. There were increases of the concentrations of TXB 2 and 6 keto PGF 1α and their ratio in serum and lung tissue during hypoxia. After use of cyclooxygenase inhibitor (indomethacin) in vivo and in vitro , HPV was augmented respectively, but after use of lipoxygenase inhibitor (diethylcorbamazine) or leukotriene receptor blocker (LY 171883), HPV was attenuated. It was suggested that LTs mediated pulmonary vasoconstriction, PGs inhibited pulmonary vasoconstriction and they played a modulating role during hypoxia.
