Posted by not exactly on March 5, 2003, at 2:56:34
In reply to Re: Dopamine agonists, posted by Michael Bell on March 4, 2003, at 23:01:38
> ... I actually disagree with people who claim dopamine levels are too low. Quite the opposite, I think we have high levels of dopamine but LOW NUMBER OF RECEPTORS/POOR TRANSMISSION.
> ... people with SP have substantially less number of D2 receptors than normal subjects, and they speculate that this may be a result of downregulation due to chronically high levels of dopamine in the brain.Fascinating! I really like this theory, because it finally explains some things that never made sense before. For example, it would explain why I responded so well to Mirapex (a dopamine agonist) but after a while it completely "pooped out". Perhaps at first it improved the stimulation of the too-sparse dopamine receptors, but eventually there was a compensatory further downregulation. MAOIs would probably have the same limitation. What sort of drug would enhance dopamine transmission without causing this compensation? A dopamine reuptake inhibitor? A pre-synaptic antagonist? Seems like what is really needed is a med that interferes with the downregulation compensation process.
And how could one reverse the downregulation that had already taken place? Would REDUCING the dopamine levels cause the receptors to become more sensitive? Maybe an antipsychotic/neuroleptic would, in the long term, induce an UPregulation? What do you think?
- Bob
poster:not exactly
thread:205134
URL: http://www.dr-bob.org/babble/20030301/msgs/206068.html