Daskalopoulos D A, Rimele T J, Flavahan N A, Vanhoutte P M
Gen Pharmacol. 1987;18(2):193-6. doi: 10.1016/0306-3623(87)90249-7.
Experiments were designed to determine how flunarizine affects contractions of cutaneous veins to alpha-adrenergic activation. Rings of canine saphenous vein were mounted at optimal length for isometric tension recording in organ chambers filled with physiological salt solution. At concentrations higher than those needed to inhibit KCl-induced contractions, flunarizine inhibited the contractile responses evoked by alpha 2-adrenergic agonists (B-HT 920, xylazine), partial (St-587) and full (cirazoline, phenylephrine) alpha 1-adrenergic agonists and the combined alpha 1-/alpha 2-adrenergic agonist, norepinephrine. The inhibitory effect of flunarizine against alpha 2-adrenergic responses was similar to that produced by other calcium-antagonists and results presumably from inhibition of the influx of extracellular calcium. The inhibitory effect of flunarizine against alpha 1-adrenergic responses was greater than expected and appears to result from competitive antagonism of alpha 1-adrenoceptors (pA2 = 5.79). Therefore, flunarizine can decrease adrenergic contractile responses by depressing the influx of extracellular calcium and by blocking postjunctional alpha 1-adrenoceptors.
实验旨在确定氟桂利嗪如何影响皮肤静脉对α-肾上腺素能激活的收缩反应。将犬隐静脉环安装在器官腔中，以最佳长度进行等长张力记录，器官腔中充满生理盐溶液。在高于抑制氯化钾诱导的收缩所需浓度时，氟桂利嗪抑制由α2-肾上腺素能激动剂（B-HT 920、赛拉嗪）、部分（St-587）和完全（可乐定、去氧肾上腺素）α1-肾上腺素能激动剂以及联合的α1-/α2-肾上腺素能激动剂去甲肾上腺素引起的收缩反应。氟桂利嗪对α2-肾上腺素能反应的抑制作用与其他钙拮抗剂产生的作用相似，推测是由于抑制细胞外钙的内流。氟桂利嗪对α1-肾上腺素能反应的抑制作用大于预期，似乎是由于对α1-肾上腺素能受体的竞争性拮抗作用（pA2 = 5.79）。因此，氟桂利嗪可通过抑制细胞外钙内流和阻断节后α1-肾上腺素能受体来降低肾上腺素能收缩反应。
