Studies on the calcium antagonistic action of tetrandrine: VIII. Antagonistic effects of tetrandrine on ouabain-induced contraction of coronary arterial strips

Abstract

The antagonistic effects of tetrandrine (Tet) on ouabain-induced contraction were studied in swine coronary arterial strips.

Like verapamil (Ver), the contraction evoked by ouabain (Oub) 0.85 μM, the synergistic effect of Oub 85 nM and Ca⁺⁺ 2–16 mM, and the response to electrical stimulation in the presence of Oub 85 nM were all inhibited by Tet (10 μM-1.2 mM), although these effects were less potent than those of Ver.

All these pharmacological actions of Tet and Ver were reversed by the addition of extra Ca⁺⁺ to the bathing medium.

The results we obtained confirm that Tet is a Ca⁺⁺-antagonist of plant origin.

Keywords

tetrandrine / iproveratril / ouabain / calcium-antagonist / coronary artery strips of swine

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