Acetylcholine: how does it work?
 

Hi, there is something I do not understand. It may be because I totally get it wrong altogether, please help me understand.

Some MG patients are anti-AChR positive, which means they have antibodies agains the acetylcholine receptors, which are the ones that respond to the binding of the neurotransmitter acetylcholine. There are different kind of AChR; the nicotinic and the muscarinic. The antibodies attack one kind of receptor; the Nm type: the nicotinic receptors located in the neuromuscular junction which causes the contraction of skeletal muscles by way of end-plate potential.

Now, I wonder about the following:

1) here's a table where you can read what drug has a positive or negative influence on the different receptors, like mestinon (pyridostigmine)wikipedia
I see more than only the drugs used to treat MG, f.e. I see Nicotine has a + for Nm too. Does this mean nicotine can help us?!

2) is there a connection between MG or Mestinon, and the brain? I just can't get to the point of understanding. I read one those nicotinic receptors are in the brain too. I don't think it's the Nm receptors, so probably the ones in the brain do not get attacked by dear antibodies. However, in the table it says mestinon has + for effect on all the receptors. Though I thought mestinon does not pass the brain blood barriere.

Anyway, something I find interesting and really want to know more about. :D

Mestinon does not normally cross the blood brain barrier to any great extent. It should not effect the brain at all; however, if I get on higher levels of it, I will get nervous. It probably does cross over just a little bit.

I don't know if nicotine can help or not, but I am reasonably sure that my doctor won't recommend smoking.

However, I'm still interested in this part. I mean, smoking (or using a nicotine patch, or a more medical approach) simply can't be as harmful as the medicine I use now. Yes of course, long term it will cause all kinds of nasty problems, but so does prednisone.
Anyway, most of all I'm curious about the chemical way it may or may not be beneficial.

Here's a guy with MG who was a heavy smoker, and when he tried a nicotine patch, his symptoms got much worse. The article (I can only see the abstract) speculates that it was like a cholinergic crisis.

http://www.ncbi.nlm.nih.gov/pubmed/9296128

Abby