Posted by chemist on May 19, 2004, at 13:25:55
In reply to Re: Chemist...questionChemist » chemist, posted by chess on May 19, 2004, at 7:01:18
> > you asked if K is hitting fewer GABA receptors with respect to time or if the same receptors were being hit but with lower ``strength:'' it is the latter that is closest to the correct answer. the presence of a more lipophilic derivative of K (the result of miking a nitro group into a primary amino group in the 7 position) - which is pharmacologically active - means that this metabolite will stay around in the brain longer, and i am not aware of any change in specificity for the BZD site in the GABA type A receptor.
> -----that's interesting, i was expecting fewer gaba receptors being hit to have been the answer.
> so then why is the K metabolite less potent than the parent K?
>
>
actually, the affinity is only for the A type GABA receptor, so in any case, there is only one receptor involved....the interaction at the benzodiazepine binding site in re: the amino vs. the nitro group has to do with higher binding affinity for the parent due to direct hydrogen bonding or water-mediated hydrogen bonding with the higly diffuse and electron-rich number of lone-pairs, in contrast to the amino, which is less likely to bind as tightly. thus, it will be eliminated faster than the parent.....hope this helps, all the best, chemist
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thread:347588
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