Chemical antagonists impede the normal function of a system. They function to invert the effects of other molecules. The effects of antagonists can be seen after they have encountered an agonist, and as a result, the effects of the agonist is neutralized. Antagonists such as dopamine antagonist slow down movement in lab rats. Although they hinder the joining of enzymes to substrates, Antagonists can be beneficial. For example, not only do angiotensin receptor blockers, and angiotensin-converting enzyme (ACE) inhibitors work to lower blood pressure, but they also counter the effects of renal disease in diabetic and non-diabetic patients. Chelating agents, such as calcium di sodium defeated, fall into the category of antagonists and operate to minimize the lethal effects of heavy metals such