Godfraind T
Eur J Pharmacol. 1979 Jan 15;53(3):273-9. doi: 10.1016/0014-2999(79)90133-x.
The action of cinnarizine and flunarizine on the relaxant effect of isoprenaline was studied in the isolated rat aorta and was compared with the action of papaverine. The results show that isoprenaline-induced relaxation and K+ contraction were reduced. On the contrary, in the presence of papaverine, isoprenaline relaxation and K+ contraction were reduced. On the contrary, in the presence of papaverine, isoprenaline relaxation was enhanced by cinnarizine and flunarizine at concentrations which were lower that those required for inducing an inhibition of the contraction evoked by K+ in the presence of 1.25 mM CaCl2; with concentrations higher than 10(-8) M both isoprenaline relaxation was enhanced and K+ contraction was depressed in a dose-dependent manner. In aged rats, isoprenaline-induced relaxation was tachyphylactic. The tachyphylaxis was prevented by cinnarizine and flunarizine. The present observations indicate that several processes might be responsible for potentiating isoprenaline action.
在离体大鼠主动脉中研究了桂利嗪和氟桂利嗪对异丙肾上腺素舒张作用的影响，并与罂粟碱的作用进行了比较。结果表明，异丙肾上腺素诱导的舒张和钾离子收缩均减弱。相反，在罂粟碱存在的情况下，桂利嗪和氟桂利嗪在低于在1.25 mM氯化钙存在下抑制钾离子诱发收缩所需浓度时，可增强异丙肾上腺素的舒张作用；浓度高于10(-8) M时，异丙肾上腺素的舒张作用增强，钾离子收缩则呈剂量依赖性抑制。在老年大鼠中，异丙肾上腺素诱导的舒张出现快速耐受性。桂利嗪和氟桂利嗪可预防这种快速耐受性。目前的观察结果表明，可能有几个过程导致异丙肾上腺素作用增强。
