Studies on the calcium antagonistic action of tetrandrine: VI. Comparison of effects of tetrandrine, verapamil and propranolol on myocardial blood flow

Abstract

By⁸⁶RbCl-extraction method, the effects of tetrandrine (Tet), verapamil (Ver) and propranolol (Pro) on myocardial blood flow of mice were studied. Both I.P. Tet 100 mg/kg and Ver 5 mg/kg increased the blood flow, whereas I.P. Pro 30 mg/kg did not. Pro counteracted significantly the increase of myocardial blood flow by isoproterenol, while Tet and Ver failed. On the other hand, Tet and Ver markedly antagonized the increase of myocardial blood flow by CaCl₂, but Pro did not.

The results indicate that unlike the β-receptor blocking agent Pro, Tet may be a calcium antagonist similar to Ver.

Keywords

tetrandrine / iproveratril / propranolol / ⁸⁶RbCl / myocardial blood flow

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