A patient is a 54 year old male who was admitted to the hospital with a severe wound infection in his leg.He is malnourished and in poor health before his arrival. His condition has continued to deteriorate, and septic shock has been diagnosed. His laboratory values reveal decreasing fibrinogen and platelet levels. You are unable to maintain an acceptable MAP with IV fluids. The physician orders an infusion of Dopamine. What is the action of this medication?