Hamilton C A, Jardine E, Sumner D J, Reid J L
Clin Exp Pharmacol Physiol. 1987 Feb;14(2):77-85. doi: 10.1111/j.1440-1681.1987.tb00960.x.
The effects of the calcium antagonists verapamil and nifedipine on mean arterial blood pressure, heart rate and pressor responses to a range of alpha-adrenoceptor agonists were examined in male normotensive New Zealand white rabbits and in rabbits with perinephritis hypertension. Verapamil and nifedipine caused a greater fall in mean arterial pressure in hypertensive compared to normotensive rabbits both when the fall was expressed as an absolute and as a percentage change. Effects on heart rate were similar in normotensive and hypertensive animals. Pressor responses to phenylephrine were attenuated by nifedipine and verapamil in normotensive and hypertensive rabbits. Pressor responses to alphamethyl noradrenaline were also attenuated by nifedipine, but pressor responses to BHT 920 were not significantly altered by either calcium antagonist in normotensive or hypertensive rabbits at the dose used. Thus the calcium antagonists had a greater effect on alpha 1 - than alpha 2-adrenoceptor mediated responses in both normotensive and hypertensive rabbits. Hypertensive animals showed an increased responsiveness to phenylephrine and alphamethyl noradrenaline but not BHT 920 compared to normotensives. This difference remained after treatment with both the calcium antagonists.
在雄性血压正常的新西兰白兔和患有肾盂肾炎高血压的兔子中，研究了钙拮抗剂维拉帕米和硝苯地平对平均动脉血压、心率以及对一系列α-肾上腺素能受体激动剂的升压反应的影响。与血压正常的兔子相比，维拉帕米和硝苯地平使高血压兔子的平均动脉压下降幅度更大，无论是以绝对下降值还是以百分比变化来表示。血压正常和高血压动物对心率的影响相似。在血压正常和高血压的兔子中，硝苯地平和维拉帕米均减弱了对去氧肾上腺素的升压反应。硝苯地平也减弱了对α-甲基去甲肾上腺素的升压反应，但在所使用的剂量下，两种钙拮抗剂对血压正常或高血压兔子对BHT 920的升压反应均无显著改变。因此，在血压正常和高血压的兔子中，钙拮抗剂对α1-肾上腺素能受体介导的反应比对α2-肾上腺素能受体介导的反应影响更大。与血压正常的动物相比，高血压动物对去氧肾上腺素和α-甲基去甲肾上腺素的反应性增加，但对BHT 920的反应性未增加。在用两种钙拮抗剂治疗后，这种差异仍然存在。
