Posted by linkadge on May 21, 2016, at 15:42:54
In reply to Dopamine antagonism, posted by J Kelly on May 21, 2016, at 7:59:49
Both Zyprexa and perphenazine are dopamine antagonists. But, they are also (to some extent) serotonin antagonists. Some of the clinical effect is due to dopamine antagonism, some is due to serotonin antagonism.
A dopamine (receptor) antagonist, is something that blocks a dopamine receptor. So, while the same amount of dopamine may be released by the brain the dopamine signal is not completed as the post synaptic receptor (which is activated by the dopamine) is blocked.
Its like an antihistamine. The antihistamine blocks the histamine which is released in an allergic reaction. So, while the same amount of histamine is floating around, you don't have the allergic reaction as the histamine receptors which are normally activated by histamine are blocked.
Now, there are different subtypes of dopamine receptors (like d1, d2, d3 etc) which have different functions in different parts of the brain. Different drugs block (or don't block) these different dopamine receptors to varying degrees.
poster:linkadge
thread:1089116
URL: http://www.dr-bob.org/babble/20160501/msgs/1089119.html