Muscle drug storage

At present, the only available drug that stimulates glucose transport is insulin. Insulin increases the abundance of the GLUT4 in plasma membranes of adipose and muscle cells by its recruitment from intracellular storage sites (for a detailed description of its mechanism, see Chapter Diabetes Mellitus). 

Muscle. Binding of drugs to components within the muscle may create the long-term storage of these compounds. Various agents may be actively transported into the muscle cell and may form reversible bonds to intracellular structures such as proteins, nucleoproteins, or phospholipids. An example is the antimalarial drug quinacrine. 

The only muscle relaxant available that exerts its effect directly on the skeletal muscle cell is dantrolene sodium (Dantrium).40,102 This drug works by impairing the release of calcium from the sarcoplasmic reticulum within the muscle cell during excitation (Fig. 13 -3).56,89 In response to an action potential, the release of calcium from sarcoplasmic storage sites initiates myofilament cross-bridging and subsequent muscle contraction. By inhibiting this release, dantrolene attenuates muscle contraction and therefore enhances relaxation. 

Muscle relaxation is caused by various mechanisms, such as depression of ACh synthesis (e.g, hemicholinium), storage (vesamicol) and release (magnesium, botulinum toxin) and depression of muscle activity by drugs such as dantrolene and baclofen,... 

---