颈交感神经干离断对妊高征大鼠胎盘血供及去甲肾上腺素和一氧化氮的影响

Effects of transection of cervical sympathetic trunk on blood supply to placenta and plasma norepinephrine and nitric oxide in rats with pregnancy hypertension

目的研究颈交感神经干离断(TCST)对妊高征(PIH)大鼠子宫动脉血流及去甲肾上腺素(NE)、一氧化氮(NO)的影响。方法 妊娠的Wistar大鼠,随机分5组,对照组(A):自孕14 d开始皮下注射生理盐水至孕20 d。实验组1(B1)、实验组2(B2):皮下分别注射左硝基精氨酸甲酯(L-NAME)12.5 mg/100 g、6.25mg/100 g,余同A。手术组(C):孕14d行右TCST,余同B1。假手术组(D):孕14 d行右颈交感神经干分离,但不离断,余同B1。孕21 d测定子宫动脉血流并经腹主动脉取血测定NE、NO含量。结果 (1)收缩期子宫动脉平均血流、收缩期和舒张期子宫动脉平均血流,B1、B2组明显低于A组(P<0.01、0.05);B1组明显低于B2组(P<0.01、0.05);C组明显高于B1组(P<0.01);左、右侧子宫动脉血流相比差异无显著性(P>0.05)。(2):NE含量B1、B2组明显高于A组(P<0.01);B1组明显高于B2组(P<0.05);C组明显低于B1组(P<0.01)。(3)NO含量B1、B2组明显低于A组(P<0.01);B1组明显低于B2组(P<0.01);C组明显高于B1组(P<0.01)。结论TCST可增加NO的合成和子宫动脉的血流量,降低PIH大鼠增高的交感神经活性。

Objective To investigate the effects of transection of cervical sympathetic trunk (TCST) on the blood flow of uterine artery (BFUA) and plasma concentrations of norepinephrine (NE) and nitric oxide (NO) in rats with pregnancy hypertension (PIH) . Methods Forty pregnant Wistar rats weighing 240-270 g were randomly divided into 5 groups with 8 animals in each group: control group( group C) , L-NAME induced hypertension groupl and 2 (group Bl, B2); TCST group and sham operation group. In control group no hypertension was induced. In group Bl and B2 hypertension was induced with L-NAME 12.5 mg.100-1 or 6.25 mg. 100-1 injected subcutaneously from 14 th to 20 th day of gestation. In TCST group TCST was performed on the 14th day of gestation and hypertension was induced as in group B1. In sham operation group cervical sympathetic trunk was exposed but not transected on the 14 th day of gestation and hypertension was induced as in group Bl. BFUA was measured and blood samples were taken from abdominal aorta for determination of plasma NE and NO concentrations on the 21 st day of gestation. Results (1) The mean BFUA during systole and systole + diastole was significantly lower in group Bl and B2 than that in group C ( P < 0.05 or 0.01) . BFUA in group Bl was significantly than that in group B2 and TCST group (P < 0.01). There was no significant difference in blood flow between right and left uterine artery (P > 0.05). (2) The plasma NE levels in group Bl and B2 were significantly higher than in that in group C (P < 0.01). The plasma NE level in group Bl was significantly higher than that in group B2 and TCST group (P <0.05 or 0.01). (3) The plasma NO levels in group Bl and B2 were significantly lower than in group C (P < 0.01). Plasma NO level in group Bl was significantly lower than that in group B2 and TCST group (P < 0.01) .Conclusion TCST can increase the plasma NO content and BFUA, and decrease the elevated sympathetic activity in rats with PIH.