Digitalis lactone and a triple-repeating sugar called a glycoside. Digitalis works by inhibiting sodium-potassium ATPase. This results in an increased intracellular concentration of sodium ions and thus a decreased concentration gradient across the cell membrane. This increase in intracellular sodium causes the Na/Ca exchanger to reverse potential, i.e., transition from pumping sodium into the cell in exchange for pumping calcium out of the cell, to pumping sodium out of the cell in exchange for pumping calcium into the cell. This leads to an increase in cytoplasmic calcium concentration, which improves cardiac contractility. Under normal physiological conditions, the cytoplasmic calcium used in
Where Do We Go from Here? (1945 film) cuts were made in his proposed score for "Where Do We Go from Here", most of his work with Ira Gershwin remains, including a lengthy mock-opera bouffé aboard Columbus' ship during which the crew threatens to mutiny. Co-stars June Haver and Fred MacMurray met while working on this film, and were later married. "Where Do We Go from Here?" has never been released on home video. A recording taken directly from the soundtrack of the film was released on LP (Ariel KWH 10) and a set of rehearsal recordings performed by Kurt Weill and Ira Gershwin is currently available on