Schwietzer G, Distler A, Reeck S, Thiede H M, Philipp T
J Hypertens Suppl. 1983 Dec;1(2):102-4.
From animal experiments it has been suggested that calcium antagonists owe their antihypertensive potency to a diminished sensitivity of the resistance vessels to circulating noradrenaline. We studied the effects of two calcium antagonists, nifedipine and verapamil, on blood pressure, reactivity to exogenous noradrenaline and plasma noradrenaline concentration in 10 patients with essential hypertension. In a cross-over comparison the patients were treated with nifedipine and verapamil for four weeks each. Both calcium antagonists led to a similar drop in arterial pressure. Resting plasma noradrenaline did not change during either treatment whereas a slight increase (P less than 0.05) in stimulated noradrenaline levels was observed during nifedipine treatment. The hypotensive effect of nifedipine was associated with a marked reduction (P less than 0.01) in the pressor effect of noradrenaline whereas no change in pressor response could be found during verapamil treatment. The results obtained suggest that an impairment of the pressor response to noradrenaline is not a general prerequisite for the antihypertensive action of calcium antagonists.
动物实验表明，钙拮抗剂的降压效力源于阻力血管对循环去甲肾上腺素的敏感性降低。我们研究了两种钙拮抗剂硝苯地平和维拉帕米对10例原发性高血压患者的血压、对外源性去甲肾上腺素的反应性及血浆去甲肾上腺素浓度的影响。采用交叉对照，患者分别接受硝苯地平和维拉帕米治疗，各为期四周。两种钙拮抗剂均使动脉压出现相似程度的下降。在任一治疗期间，静息血浆去甲肾上腺素水平均无变化，而在硝苯地平治疗期间，刺激后的去甲肾上腺素水平有轻微升高（P<0.05）。硝苯地平的降压作用与去甲肾上腺素升压作用的显著降低（P<0.01）相关，而在维拉帕米治疗期间，升压反应未发现变化。所得结果提示，对去甲肾上腺素升压反应的损害并非钙拮抗剂降压作用的普遍前提条件。
