physo Q - bee

[ArchivalUser]

You give a patient a drug that causes intracellular sodium, [Na+]i, in ventricular cells to increase. Which of the following statements regarding this condition is correct?

A. The drug has stimulated the Na-K pump in ventricular cells.
B. The rate of Ca2+ efflux from ventricular cells via Na-Ca exchange will increase.
C. Intracellular Ca2+ will increase in ventricular cells.
D. The inwardly directed sodium concentration gradient in ventricular cells will be increased

explain plz.

[ArchivalUser]

C, if Na-K pump is inhibited-there will be intracellular build up of Na+. This will cause corresponding increase in intracellular Ca++ (since each Na+ extrusion also cause corresponding Ca++ efflux from the cell). This is how a cardiac glycoside should work.