Eyer C L, Johnson W E
Arch Int Pharmacodyn Ther. 1979 Jan;237(1):119-27.
The fetal rat heart in organ culture was used to study the interaction of calcium with the cardioactive agents. McN-2165 is an agent that produces negative chronotropism and elevation in cyclic AMP levels in this preparation. A concentration of 2.76 mM calcium ion antagonized the negative chronotropic action and prevented the cyclic AMP elevation produced by this agent. Positive chronotropic actions of isoproterenol were prevented by decreasing the calcium level below 1.84 mM.
采用器官培养的胎鼠心脏来研究钙与心脏活性药物的相互作用。McN - 2165是一种在此实验制剂中产生负性变时作用并使环磷酸腺苷（cAMP）水平升高的药物。2.76 mM的钙离子浓度可拮抗其负性变时作用，并阻止该药物引起的环磷酸腺苷水平升高。将钙水平降至1.84 mM以下可阻止异丙肾上腺素的正性变时作用。
