【摘要】 目的　探讨慢性缺氧 (O2 )高二氧化碳 (CO2 )对大鼠肺动脉L 精氨酸 (L Arg)转运的影响与吸氧的作用。方法　将 4 0只大鼠以随机区组设计法分成 4组 ,用 0 2mmol/L和 5 0mmol/L [3 H] Arg将肺动脉孵育 ,测定其对 [3 H] L Arg的摄取率、一氧化氮合酶 (NOS)活性与一氧化氮 (NO2 /NO3)含量。每组 1 0只。正常对照组 (A组 )、慢性缺O2 4周后伴高CO2 4周组 (B组 )、慢性缺O2 4周伴高CO24周后吸空气 4周组 (C组 )及慢性缺O2 4周伴高CO2 4周后吸O2 4周组 (D组 )。结果　 (1 )肺动脉平均压 (mPAP)、右心室 (RV)和左心室 +室间隔 (LV +S)重量比值 (RV/LV +S) :B组 (33% )与A组(35 % )比较差异有显著性 (P均 <0 0 1 ) ;D组 (2 4 % )与C组 (2 4 % )比较 ,差异也有显著性 (P均 <0 0 5 )。 (2 )离体孵育的肺动脉摄取低浓度 (0 2mmol/L)和高浓度 (5 0mmol/L) [3 H] L Arg比较 :B组分别为 [(3 0 4± 0 1 6 ) μmol·g-1 min-1 ]、[(8 1 2± 0 1 4 ) μmol·g-1 ·min-1 ],A组分别为 [(4 6 2± 0 5 5 )μmol·g-1 ·min-1 ]、[(1 1 2 4± 1 0 2 ) μmol·g-1 ·min-1 ],A、B两组比较差异有显著性 (P均 <0 0 1 ) ;而D组分别为 [(4 30± 0 1 8) μmol·g-1 ·min-1 ]、[(1 2 31± 0 6 5 ) μmol·g-1 ·m更多还原

【Abstract】 Objective To investigate the effect of chronic hypoxia hypercapnia and oxygen inhalation on L arginine transport in rat pulmonary artery Methods Forty male Sprague Dawley rats were randomly divided into four groups: normal control group (A), the group of 4 week hypoxia hypercapnia after 4 week hypoxia (B), the group of 4 week oxygen inhalation (D) 4 week exposure to air (C) after 4 week hypoxia and 4 week hypoxia hypercapnia Changes in pulmonary artery L arginine (L Arg) transport, nitric oxide synthase (NOS) activity, plasma nitrite (NO 2 /NO 3 ) concentration and L Arg level in rats were measured Results (1) The mean pulmonary artery pressure (mPAP) and weight ratio of right ventricle to left ventricle plus septum (RV/LV+S) of B group were higher than those of A group (33% and 35%, respectively, P< 0 01), with the D group lower than C group (24% and 24%, respectively, P< 0 05) (2) At low (0 2 mmol/L) or high (5 0 mmol/L) concentration of L Arg,the velocity of L Arg transport in B group was lower than that in A group [(3 04±0 16 vs 4 62±0 55) μmol·g -1 ·min -1 and (8 12±0 14 vs 11 24±1 02) μmol·g -1 ·min -1 , respectively, P< 0 01], and in D group higher than in C group [(4 30±0 18 vs 3 80±0 21)μmol·g -1 ·min -1 and [(12 31±0 65 vs 10 04±1 28) μmol·g -1 ·min -1 , respectively, P< 0 01] (3) The activity of pulmonary artery tNOS and iNOS in B group was significantly higher than that in C group [(3 82±0 42 vs 2 59±0 22) μnmol·g -1 ·min -1 and (3 07±0 30 vs 1 62±0 10) nmol·g -1 ·min -1 respectively, P< 0 01], but cNOS in B group was lower than that in NC group [(0 75±0 16 vs 0 93±0 10) nmol·g -1 ·min -1 , P< 0 01] The activity of tNOS and cNOS was not significantly different between D group and C group ( P> 0 05); However,iNOS was lower in D group than in C group [(1 97±0 18 vs 2 25±0 17) nmol·g -1 ·min -1 , P< 0 05] (4) Plasma NO 2 /NO 3 content of B group was decreased by 21%, compared with C group ( P< 0 01); and D group was increased by 89% ( P< 0 01), compared with C group (5) Plasma L Arg level was not significantly different among the four groups ( P >0 05) Conclusion The L Arg transport injury of the pulmonary artery might be the key cause for the decrease of nitric oxide generation in rats with chronic hypoxia hypercapnia induced pulmonary hypertension Oxygen inhalation was found to improve L Arg transport in the injured arteries更多还原