钩藤碱对自发性高血压大鼠的降压作用及其对血管的调节机制探讨

目的研究钩藤碱连续给药后对自发性高血压大鼠(SHR)收缩压(SBP)的影响及其对血管的调节机制。方法取雄性SHR,随机分为模型组(等容量蒸馏水),卡托普利阳性对照组(6.25 mg/kg),钩藤碱低、中、高剂量(1.25、2.50、5.00 mg/kg)组,另取SD雄性大鼠作为对照组(等容量蒸馏水),各给药组连续ig给药21 d,测定给药前和给药第7、14、21天的大鼠尾动脉SBP,末次给药后采血,检测血浆血管紧张素II(Ang II)、非对称二甲基精氨酸(ADMA)、血管紧张素II 1型受体(AT1R)和血清NO、一氧化氮合酶(NOS)水平。结果与模型组比较,钩藤碱各剂量组可显著降低SHR的SBP值;模型组大鼠血浆Ang II、ADMA、AT1R水平显著升高,且血清中NO和NOS水平显著下降,而钩藤碱能够逆转上述指标的改变(P<0.05、0.01)。结论钩藤碱对SHR有显著降低SBP作用,能降低血浆Ang II、ADMA水平,升高血清NO和NOS水平,有保护血管内皮功能的作用。

Antihypertensive effect and vascular regulation mechanism of rhynchophylline on spontaneously hypertensive rats

Objective To observe the effect of rhynchophylline (Rhy) on systolic blood pressure (SBP) with different time after administration in spontaneously hypertensive rats (SHR), and explore the protective effect on vascular endothelial cells of Rhy after long-term administration. Methods Male SHR were randomly divided into model , positive control (Captopril 6.25 mg/kg), low-, mid-, and high-dose (1.25, 2.50, 5.00 mg/kg) Rhy groups. Other SD rats were included as the control group. Rats in the model and control groups were given the same volume of distilled water once daily for 21 d. Rat tail artery SBP was measured before administration and day 7, 14, and 21 during the administration. The levels of plasma Ang II, ADMA, AT1R, and serum NO, NOS were detected after the last administration underwent blood sampling. Results Compared with the model group, Rhy reduced SBP significantly. Moreover, the plasma Ang II, ADMA, and AT1R levels were up-regulated, and the serum NO and NOS levels were decreased in the model group, which could be reversed by the treatment of Rhy (P < 0.05, 0.01). Conclusion Rhy could reduce the SBP of SHR significantly, decrease plasma Ang II, ADMA, and AT1R levels, and promote serum NO and NOS levels, which has the protection of vascular endothelial function.