前胡丙素对两种高血压模型大鼠尾动脉的钙拮抗作用

Calcium antagonistic effects of praeruptorin C on tail artery in two models of hypertensive rats

目的：观察前胡丙素（Ｐｒａ－Ｃ）对两种高血压模型大鼠尾动脉的钙拮抗作用。方法：采用两种高血压模型大鼠离体血管功能实验方法。结果：Ｐｒａ－Ｃ对氯化钾除极化所致正常、ＤＯＣＡ－ｓａｌｔ型、肾血管型高血压大鼠尾动脉呈非竞争性拮抗作用，其ｐＤ′２分别为４．６４、４．７７和５．２７，ＩＣ５０分别为１６．８８、１４．３７、６．４３μｍｏｌ·Ｌ－１，Ｐｒａ－Ｃ明显抑制５－ＨＴ所致正常、ＤＯＣＡ－ｓａｌｔ型、肾血管型高血压大鼠尾动脉慢速收缩反应，其中对肾血管型高血压大鼠的抑制作用较强，而对５－ＨＴ所致３组大鼠尾动脉的快速反应均无抑制作用。结论：Ｐｒａ－Ｃ对肾血管型高血压大鼠尾动脉的钙拮抗作用强于ＤＯＣＡ－ｓａｌｔ型高血压大鼠和正常大鼠，可能与两种高血压大鼠模型高血压形成机制不同有关。

AIM: To observe the calcium antagonistic effects of praeruptorin C(Pra C) on tail artery in two models of hypertensive rats. METHODS: The isometric tension of tail artery rings from two models of hypertensive rats were measured by a forcedisplacement transducer using experimental method of isolated blood vessel function. RESULTS:In the isolated tail artery of normotensive, DOCA salt hypertensive and renovascular hypertensive rats, Pra C was shown to inhibit the contraction induced by potassium depolarization and shifted the concentration response curve nonparallely to the right. The pD′ 2 values were found to be 4 64, 4 77 and 5 27 with IC 50 values of 16 88, 14 37 and 6 43 μmol·L -1 respectively. Pra C significantly inhibited extracellular calcium influx contractions but not inhibited intracellular calcium release contractions induced by serotonin in normotensive, DOCA salt hypertensive and renovascular hypertensive rats. CONCLUSIONS: The calcium antagonistic effects of Pra C in renovascular hypertensive rats is greater than that in DOCA salt hypertensive rats and normotensive rats, and it is probably related to different mechanisms of two models of hypertensive rats.