Posted by BrittPark on November 7, 2002, at 20:00:54
In reply to Re: Opiates = very weird, Britt?, posted by Larry Hoover on November 7, 2002, at 18:36:34
> I started looking at opiates all over again, and I'm finding some recent studies showing bizarre and seemingly contradictory effects.....one substance simultaneously acting as an agonist, inverse agonist and antagonist, in the same signalling system....dimerization of all sorts of receptors... not just opiate/opiate, but also sigma/opiate and alpha-2 adrenergic/opiate.....simultaneous up-regulation of sensitivity with down-regulation of receptor trafficking.....I don't know how on earth one is supposed to make sense of this all.
>
> Maybe opiates *are* the devils work....
>
> LarYou may be right that opiates are the devils work. Morphine and friends were not evolved for our benefit. More probably as pest control for Papaver Somniferum. Of course that doesn't mean we can't make use of and learn from opiates.
The biochemistry of opiods does seem to be exceedingly complex. I'm a biochemist by training and still find myself perplexed. What I do know is that in some cells there are mu-opiate receptors attatched to both inhibitory and excitatory G proteins. Two phenomena support this. At low concentrations pure agonists like morphine can act as antagonist and result in hyperalgesia rather than analgesia. The other is the ability of low doses of opioid antagonists like naltrexone to enhance the analgesic properties of agonists and further stop or at leas delay the development of opioid tolerance. Then there are the studies that have found that opiates cause clustering of opiate receptors but prevent endocytosis of the clusters. When a compound that stimulates endocystosis is added tolerance development is lowered, at least in vitro.
There is much to learn.
Cheers,
Britt
I think of the complex biochemistry of opioids as a good thing because it means new drug targets are likely to be found, both for pain relief and, I hope, depression.
poster:BrittPark
thread:126471
URL: http://www.dr-bob.org/babble/20021101/msgs/126889.html