心肌缺血对大鼠延髓利钠肽受体表达的影响

 目的:探讨大鼠延髓腹侧部利钠肽受体A(NPR-A)、利钠肽受体C（NPR-C）、胆碱乙酰转移酶（ChAT）和酪氨酸羟化酶（TH）的表达在心肌缺血后不同时程的动态变化。方法:大鼠分为空白对照组、假手术组和模型组。建立心肌缺血模型后，于术后3、7、14、18和28 d取材，用Western blotting方法检测延髓腹侧部吻段、尾段内NPR-A、NPR-C、ChAT和TH表达。结果:在模型复制后的上述时点，延髓腹侧部NPR-A的表达显著升高（P<0.05），NPR-C表达的升高晚于NPR-A，TH的表达显著低于空白对照组（P<0.05），在延髓腹侧部吻段ChAT的表达低于空白对照组（P<0.05），而在尾段与对照组无显著差异。结论:延髓心血管中枢内NPR-A和NPR-C的表达在心肌缺血后均显著升高，而ChAT和TH的表达则显著降低。利钠肽、ChAT和TH可能都参与了心肌缺血后心血管系统的植物神经调控。

Effect of myocardial ischemia on expression of natriuretic peptide receptors in rat medulla oblongata

AIM:To evaluate the expression of natriuretic peptide receptor A (NPR-A) and C (NPR-C), choline acetyltransferase (ChAT) and tyrosine hydroxylase (TH) in the ventral medulla oblongata after myocardial ischemia in the rats. METHODS:All rats were randomly divided into blank control group, sham group and myocardial ischemia group. After the myocardial ischemia model was established, the rats were sacrificed, and the expression of NPR-A, NPR-C, ChAT and TH in the rostral ventral medulla oblongata and caudal ventral medulla oblongata was detected by Western blotting on day 3, day 7, day 14, day 18 and on day 28. RESULTS:On the above days after modeling, the expression of NPR-A in ventral medulla oblongata of the rats was significantly increased (P<0.05). The expression of NPR-C was also increased, but later than NPR-A. The expression of TH was significantly decreased (P<0.05). The expression of ChAT in the rostral ventral medulla oblongata was lower than that in blank control group (P<0.05), and had no significant difference as compared with blank control group in the caudal ventral medulla oblongata. CONCLUSION:In medulla oblongata, the expression of NPR-A and NPR-C in the central cardiovascular region significantly increases after myocardial ischemia, while the expression of ChAT and TH decreases markedly. The natriuretic peptide, ChAT and TH may participate in the autonomic nervous control of cardiovascular system after myocardial ischemia.