Natural/synthetic. Dopamine is a naturally occuring catecholamine with numerous physiologic functions including neural transmission and BP regulation. Dobutamine is a synthetic drug used for testing and cardiac stimuation.
Dopamine. Found a great discussion here: http://allnurses. Com/cardiac-nursing/whats-the-difference-12149.Html.
Receptors. These three medications are used to support the heart and cardiovascular system ie. Blood pressure and heart rate. They are known as sympathomimetics and have a similar response to what you would think of as adrenaline. Each has variable effect on either heart rate, heart function (in terms of strength of 'squeeze') and on blood vessels which would translate to higher blood pressure.