Discussion
Saturday October 10, 1998 - Question 1
Which of the following statements about the pharmacology/toxicology of calcium and the calcium channel blockers is correct?
A. A specific receptor that is affected by the calcium channel blockers has not been identified.
B. The initial amount of calcium allowed into smooth or cardiac muscle depends on the proportion of open calcium channels on the cell surface.
C. Alpha-adrenergic stimulation increases the number of open calcium channels on the cell surface.
D. When calcium enters the myocyte, the sarcoplasmic reticulum is signaled by both calcium and intermediary proteins to decrease further calcium release.
E. The activity of troponin-C, which is involved
in muscle contraction, is not affected by calcium.