Effects of tetrandrine, verapamil and propranolol on contractility and camp level 'of isolated rabbit left atria
Abstract
A comparison of the effects of tetrandrine (Tet), verapamil (Ver) and propranolol (Pro) on cAMP level and force of contraction was made on isolated left atrial strips of rabbits. Pro antagonized the increase of cAMP and force of contraction caused by iso-prenaline, but Tet and Ver did not. This indicates that Tet and Ver do not react with B—adrenergic receptor. These results are in accordance with our previous experiments on cat papillary muscle and rabbit right atrium and sup-port further that Tet may be a Ca++ an-tagonist, not a B-receptor blocker.
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