Contractile versus proliferative

V. COMPARISON OF MITOGEN-ACTIVATED PROTEIN KINASE ACTIVATION IN CONTRACTILE VERSUS PROLIFERATIVE SMOOTH MUSCLE ... 

FIGURE 4 Schematic depicting the potential roles for MAPK in contractile versus proliferative (or cultured) smooth muscle. MAPK is activated in response to stimulation by growth factors, stretch, and pharmacological agents. This process can be inhibited by cAMP and cAMP-dependent protein kinase. Once activated, MAPK phos-phorylates a number of intracellular proteins (both cytoplasmic and nuclear) that result in an alteration of growth and proliferation in cultured cells. In contractile smooth muscle, MAPK phosphorylation of caldesmon may lead to alterations in muscle contractility or actin filament structure. 

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