颈动脉窦诱导型一氧化氮合酶的抑制对压力感受性反射的影响

The effect of iNOS depression of carotid sinus on baroreflex

目的 :探讨 SD大鼠颈动脉窦 (CS)诱导型一氧化氮合酶 (i NOS)与压力感受性反射 (BR)及血压的关系。方法 :合成的 i NOS反义寡核苷酸 (ASODN)和其正义链干预 SD大鼠 CS前后 ,用生理记录仪同时记录血压和心率 ,测定静脉注射苯肾上腺素 (PE)引起的加压反应和压力感受性反射敏感度 (BRS)及心率变化中点对应的血压值(MAP5 0 ) ,CS处 i NOS含量的变化通过免疫组化的方法测定 ,并对其 CS的 i NOS进行免疫组化染色分析。结果 :1i NOS- ASODN干预大鼠 CS后 ,加压反应较干预前减弱 (2 4± 3 vs 44± 6 mm Hg,P<0 .0 1,1mm Hg=0 .133k Pa) ,而 i NOS正义链干预 CS后加压反应较干预前无变化 (37± 9vs41± 7mm Hg,P>0 .0 5 ) ;2 i NOS- ASODN干预大鼠 CS后 ,MAP5 0 较干预前下降 (135± 6 vs147± 6 m m Hg,P<0 .0 1) ,压力心率曲线左移 ,而 i NOS正义链干预 CS后 ,MAP5 0 较干预前无差异 (147± 7vs146± 7mm Hg,P>0 .0 5 ) ;3i NOS- ASODN干预大鼠 CS后 ,BRS较干预前升高 (- 3.6± 0 .5 vs- 2 .3± 0 .7beat· s- 1 · m m Hg- 1 ,P<0 .0 1) ,而 i NOS正义链干预 CS后 BRS较干预前无变化 (- 2 .5± 0 .5 vs- 2 .5± 0 .6 beat· s- 1· mm Hg- 1 ,P>0 .0 5 ) ;4i NOS- ASODN干预大鼠 CS后 ,对血压无影响 (12 3±

AIM: To investigate the relation among inducible nitric oxide synthase (iNOS) gene of SD rat's carotid sinus and baroreflex and blood pressure. METHODS: Before and after the synthetic iNOS antisense oligodeoxynucleotides (iNOS ASODN) and it's sense chain affecting SD rat's carotid sinus, blood pressure and heart rate were adopted by 6 channals physical recorder to measure the pressor response and baroreceptor sensitivity(BRS) to phenlephrine(PE) and blood pressure to the midpoint of heart rate change(MAP 50 ), the content of iNOS of SD rat's carotid sinus was determined by immunohistochemistry. RESULTS:①After iNOS ASODN affecting SD rat's CS, the pressor response to PE was decreased(24±3 vs 44±6 mm Hg, P <0.01), as iNOS sense chain had no effect on pressor response to PE(37±9 vs 41±7 mm Hg, P >0.05);②after iNOS ASODN affecting SD rat's CS, MAP 50 decreased (135±6 vs 147±6 mm Hg, P <0.01), the curve of blood pressure and heart rate shifted to left, but iNOS sense chain had no effect on MAP 50 (147±7 vs 146±7 mm Hg, P >0.05); ③after iNOS ASODN affecting SD rat's CS, BRS was enhanced (-3.6±0.5 vs -2.3±0.7 beat·s -1 ·mm Hg -1 , P <0.01), as iNOS sense chain had no effect on BRS(-2.5±0.5 vs -2.5±0.6 beat·s -1 ·mm Hg -1 , P >0.05); ④iNOS ASODN affecting SD rat's CS had no effect on blood pressure(123±6 vs 121±4 mm Hg, P >0 05), and iNOS sense chain also had no effect on blood pressure (118±2 vs 121±5 mm Hg, P >0.05); ⑤after iNOS ASODN affecting SD rat's CS, the stain of iNOS immunohistochemistry was weaker than sense chain group, there were obvious difference between the results of their photo density (0.14±0.01 vs 0.19±0.02, P <0.01). CONCLUSION: After iNOS ASODN affecting SD rat's CS, the concentration of iNOS decreased, the function of BR was enhanced. It implied that iNOS and it's producing NO of carotid sinus has a negative effect on BR.