Posted by pablo1 on September 30, 2004, at 18:13:48
In reply to weird article about amphetamine methamphetamine, posted by mmcconathy on September 30, 2004, at 12:39:30
Hmm, there's a few things I don't understand in that.
What is a norepenephrine TRANSPORTER? I've heard dopamine converts to norepenephrine but not that it uses norep. pathways. I don't understand that.
Why are they using desipramine, a powerful norep. reuptake inhibitor, similar to Strattera? My pdoc says he thinks norep. has more to do with ADHD than dopamine but he didn't explain why. I think it's just cause some people respond well to strattera & he prefers to avoid "real" stimulants. Many more people respond to stimulants than strattera though so I think he's overemphasizing the importance of norep. Also the side effects are much worse and in my experience, the norep. meds all cause me problems but pure dopamine meds like amisulpride and ameneptine are much nicer without the icky side effects. I have a certain amount of anxiety & I think I've already got more than my share of noradrenaline. So still they are using norep. but the goal is prefrontal dopamine levels. Oviously these are related but I don't understand how. The article says that "Amphetamine raised norepinephrine levels more than methamphetamine did" and to me that's a problem so I probably would prefer meth to adderall. It sounds like they are saying meth works more with just dopamine and has little (or less) effect on norep and less effect on actual dopamine levels in that part of the brain. My notes say meth is a strong reuptake inhibitor and releaser for both norep & dopamine and releases seratonin also. Adderall is listed as a moderate reuptake inhibitor (no release) for both norep & dopamine. Ritalin also releases some norep. So yeah, I agree these are wierd findings. Maybe the effect they are describing is more in the prefrontal cortex versus effect on other parts of the brain or body? I don't know if their microdialysis measurement technique is the best or only way to measure these things.
Also the article states "Desipramine raised dopamine and serotonin levels but did not alter metabolite levels" I don't understand the distinction of "metabolite" levels or the significance.
> Amphetamine is more effective than methamphetamine at raising dopamine levels in the prefrontal cortex. The current study tested the hypothesis that norepinephrine transporters are involved in this difference. Using microdialysis, dopamine, norepinephrine, and serotonin were measured in the rat prefrontal cortex after administration of methamphetamine or amphetamine, with and without perfusion of desipramine. Amphetamine raised norepinephrine levels more than methamphetamine did. Desipramine raised dopamine and serotonin levels but did not alter metabolite levels. Desipramine attenuated the increase in dopamine by amphetamine while increasing the dopamine released by methamphetamine. These data suggest that methamphetamine and amphetamine differ in altering prefrontal cortical dopamine levels and in interacting with norepinephrine transporters. It is proposed that amphetamine releases dopamine in the prefrontal cortex primarily through norepinephrine transporters, whereas methamphetamine interacts minimally with norepinephrine transporters.
>
> Keywords
> Amphetamine, dopamine, medial prefrontal cortex, microdialysis, methamphetamine, norepinephrine
>
> Article ID: 484490
>
>
> http://journals.kluweronline.com/article.asp?PIPS=484490
>
>
>
> I just thoguht it was intesting, amphetamine i didnt know releases more dopamine than methamphetamine.
>
> Can i get some of your opinion's?
>
> Thanks
>
> Matt
poster:pablo1
thread:397281
URL: http://www.dr-bob.org/babble/20040927/msgs/397406.html