Effects of Calcium Antagonists on Coronary Spasm and Pulmonary Artery Contraction in Comparison to Their Antagonistic Action against K-Strophanthin in Isolated Guinea Pig Atria

Abstract

The contraction of the potassium depolarized pulmonary artery of the guinea pig was diminished by the calcium antagonists nifedipine, gallopamil, diltiazem, verapamil and prenylamine. The drugs are listed here in order of activity. The uptake of 45Ca of the depolarized pulmonary artery was reduced by nifedipine, verapamil and prenylamine in this order of activity. The depression of the coronary flow of the isolated guinea pig heart, which was brought about by barium chloride, antigenic rabbit serum or vasopressin plus oxytocin was reduced by infusion of prenylamine. The positive inotropic effect of K-strophanthin on the isolated, electrically stimulated left atrium of the guinea pig heart was reduced by gallopamil. verapamil, prenylamine, diltiazem and nifedipine in this order of activity.

Evaluation of related factors, prediction and treatment drugs of no-reflow phenomenon in patients with acute ST-segment elevation myocardial infarction after direct PCI

“…Diltiazem can significantly improve no-reflow phenomenon, which may be related to the improvement of microcirculation through stretching vasospasm. Calcium antagonists have a great advantage in improving coronary spasm ( 20 ). In addition, these antagonists open the microcirculation pathway, thus blocking the formation of microthrombosis and playing the anti-no-reflow role.…”

Perfluorochemical Perfusion of the Isolated Guinea Pig Heart

“…FRG). The contractile force was measured by means of a strain gauge bridge TF 3V20 (Hellige) as described by Lindner and Rupperi [11]. The heart rate could be calculated by elec tronic counting of the contraction impulses.…”

Hoe 263, a New Substance with Calcium Channel Antagonistic Activity

“…Relaxation was brought about by switching back to normal Tyrode's solution. After addition of the calcium channel antagonistic substance, contrac tion of the pulmonary artery by the potassium-rich solution is more or less inhibited [12].…”

“…The tissue w'as then blotted between filter paper by overrolling three times with a 350-gram weight and weighed [8]. 45Ca2* content was deter mined by liquid scintillation counting after dissolution of the tissue in 0.2 ml of a mixture (1:1) of perchloric acid (35%) and H20 2 (30%) at 80 °C for 2-3 h [8,12].…”

“…After washout, the cal cium channel antagonist was injected and 10 min later the same dose of K-strophanthin as used before was added. The depression of the positive inotropic effect by the calcium channel antagonist was then measured [ 12].…”