Inotropic influence of macrocyclic polyethers on tracheal smooth muscle.

Incubated guinea pig tracheal smooth muscle exhibited both positive and negative inotropic responses to a variety of crown ether analogs that ranged in size from 12-crown-4 to 30-crown-10 and included molecules whose lipophilicity was modified by the addition of benzo- and cyclohexo-substituents on the basic molecular framework. The inotropic influence of crown ethers may not only be due to their ionophoretic capabilities but may result from their ability to affect alterations in membrane physiology.