In order to elucidate the major mechanism of cerebral vasodilator action of brovincamine fumarate (CAS 57475-17-9) the present study was performed comparing its effects with those of d-cis-diltiazem in the isolated canine basilar artery. Brovincamine possessed a wide spectrum of inhibitory actions on the contractions of the artery produced by various spasmogens and mechanical stretch. Brovincamine was 3 to 40 times less potent than d-cis-diltiazem in the inhibitory actions. Simultaneous recordings of intracellular Ca2+ concentration and mechanical activity showed that brovincamine and d-cis-diltiazem decreased both parameters augmented by high KCl in a concentration-dependent and parallel manner. Both brovincamine and d-cis-diltiazem shifted parallel to the right the concentration-response curves for CaCl2-induced contraction of the artery constructed in the Ca(2+)-free depolarizing medium. Furthermore, Schild regression of the curves was linear with a slope of unity, indicating apparently a competitive antagonism between Ca2+ channel function/Ca2+ and brovincamine or d-cis-diltiazem. The results suggest that the cerebral vasodilator effect of brovincamine is mainly attributable to the inhibition of Ca2+ influx through the voltage-dependent Ca2+ channels, supporting the reported clinical benefits of this drug in the treatment of cerebrovascular disorders.

中文翻译：

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犬脑动脉中研究富马酸溴丙胺的钙拮抗血管舒张机制。

为了阐明富马酸溴丙胺（CAS 57475-17-9）的脑血管舒张作用的主要机制，本研究比较了其与d-顺式-地尔硫ze在分离的犬基底动脉中的作用。Brovincamine对各种痉挛源和机械拉伸产生的动脉收缩具有广泛的抑制作用。在抑制作用中，Brovincamine的效力比d-cis-diltiazem低3至40倍。同时记录的细胞内Ca2 +浓度和机械活性表明，溴乙烯胺和d-顺式-地尔硫卓以浓度依赖和平行的方式降低了高KCl增强的两个参数。brovincamine和d-顺式-diltiazem都平行向右移动，在无Ca（2+）的去极化介质中，CaCl2诱导的动脉收缩的浓度-响应曲线。此外，曲线的Schild回归呈线性，并具有一个单位斜率，这表明Ca2 +通道功能/ Ca2 +与溴长春胺或d-顺式-地尔硫ze之间存在竞争性拮抗作用。结果表明，溴丙胺的脑血管舒张作用主要归因于通过电压依赖性Ca2 +通道抑制Ca2 +流入，支持了该药物在治疗脑血管疾病中的临床益处。表明Ca2 +通道功能/ Ca2 +与溴芬卡明或d-顺式-地尔硫ze之间存在竞争性拮抗作用。结果表明，溴丙胺的脑血管舒张作用主要归因于通过电压依赖性Ca2 +通道抑制Ca2 +流入，支持了该药物在治疗脑血管疾病中的临床益处。表明Ca2 +通道功能/ Ca2 +与溴芬卡明或d-顺-地尔硫ze之间存在竞争性拮抗作用。结果表明，溴丙胺的脑血管舒张作用主要归因于通过电压依赖性Ca2 +通道抑制Ca2 +流入，支持了该药物在治疗脑血管疾病中的临床益处。