Antianginal Drugs

                           Fig: Nitrates and the Nitric Oxide Pathway

 

CALCIUM CHANNEL ANTAGONISTS (CCAs)

As  shown  in  Figure smooth muscle  contraction  is triggered  by  the  influx  of  ca2+ through voltage-regulated membrane channels. Ca2+  combines with calmodulin, and the complex activates myosin LC  kinase, the active form of which  (MLCK*) phosphorylates myosin light chains, enabling the interaction between myosin and actin.



               Fig:  Mechanisms  of Smooth Muscle Contraction