二氧化硫对大鼠颈动脉窦压力感受器反射影响的研究

The effect of sulfur dioxide on carotid sinus baroreflex in anesthetized rats

目的:探讨二氧化硫(SO2)对大鼠颈动脉窦压力感受器反射的调节作用。方法:雄性,SD大鼠,32只,随机分为对照组(n=8)、10μmol/LSO2组(Na2SO3/Na HSO3,3:1物质的量比,n=8)、100μmol/LSO2组(n=8)、1000μmol/L SO2组(n=8),应用隔离灌流方法,观察不同浓度SO2灌流液对大鼠动脉血压的变化和颈动脉窦压力感受器反射功能的影响。结果:与对照组相比,10μmol/L,100μmol/L,1000μmol/LSO2组颈动脉窦压力感受器反射均有易化作用,其平均动脉压反射性下降的最大值(RD)及最大斜率(PS)均升高,阈压(TP)、平衡压(EP)及饱和压(SP)均降低,变化幅度呈浓度依赖性。SO2各组颈动脉窦压力感受器反射机能曲线(窦内压-平均动脉压曲线,ISP-MAP曲线)较对照组向左下方移位。结论:SO2对大鼠颈动脉窦压力感受器反射活动存在易化作用,其作用机制有待进一步研究。

Objective ： To find out the effect of sulfor dioxide on carotid sinus reflex by giving sulfur dioxide as intervention on the cartoid sinus, and use isolated carotid sinus perfusion. Methods： 32 Sprague-Dawley rats [ male, （320 ± 20）g J, divided into the following 4 groups randomly： control group, 10μmol/L Na2 SO3/NaHSO3 （ SO2 deviates） group, 100μmoL/L Na2SO3/NaHSO3 group, 1 000μmol/L Na2SO3/NaHSO3 group. After anesthetization of rat, left carotid sinus areas were fully exposed. Plastic catheters were inserted into the left common carotid artery in the anterograde way （ served as inlet tube） and the external carotid artery in the retrograde way （served as outlet tube） , then different reagent of 4 groups were perfused into the carotid sinus, and the intrasinus pressure （ISP） was took down by polygraph. Meanwhile a plastic catheter was insert the left femoral artery to measure the arterial pressure（MAP） by the polygraph too. Then the functional curve for ISP-MAP relation was constructed, and the functional parameters of baroreflex such as threshold pressure （TP） , saturation pressure （SP） , equilibrium pressure （EP） , peak slope （PS） , reflex decrease of BP （RD） , and operating range （ OR ） were determined. Results： By perfusing the carotid sinus with SO2 deviates （10μmol/L, 100μmol/L, 1 000 μmol/L） , the parameters RD and PS increased, with TP, EP and SP decreased in a concentration-dependent manner, which indicated the facilitation effect of SO2 to the carotid sinus reflex. SO2 deviates per＇fusion shifted the ISP-MAP curve downward and to the left, compared with control group. Conclusion： SO2deviates showed a facilitation effect in rat carotid sinus reflex in a concentration-dependent manner.