I worked in a college neuro research lab in 1991 that had received samples of MPTP for research purposes. The project had ended before my time, but the drug was a frequent topic of conversation. We were studying various dopaminergic conditions using leeches. I still have a copy of a book documenting the various research "MPTP: A Neurotoxin Producing a Parkinsonian-like Response".
One detail of the story that I still remember: the dealers of the MPTP heroin realized they had a bad batch and cut the price to get rid of it.
I thought of the SoftCell song immediately when I saw this headline. "Tainted Drugs, woo oh oh"
That said, I have often thought there was a link between cocaine use and early parkinsons. Its interesting to see that bad opiates can also cause similar symptoms.
There is. Cocaine and most other hard stimulants cause lots of dopamine to be released in the brain. Generally when you have higher concentrations of a neurotransmitter than normal for a long time, your brain compensates for the overstimulation by reducing the number of receptors. It doesn't work in exactly the same way as this drug but the end result is the same - reduced number of dopamine neurons, which causes parkinson's symptoms.
The scary thing about this drug is that it doesn't really have anything to do with the fact that they were trying to make opiates, it just happens that if you mess up the reaction you get this really toxic byproduct. As governments keep banning new drugs, chemists (amateur and professional, but it's hard to know which is which since this is all unregulated) keep coming up with new not technically illegal ways to achieve the same effects, and it's really just a matter of time before you create something else toxic. And it's entirely possible that some designer drugs that seem safe at first can end up having bad complications later on, since they're not very well researched and understood. At least we know how toxic meth is - with research drugs, especially newly discovered ones, no one really knows what kind of damage they're doing to themselves.
Careful there - the compensatory decrease in number of receptors is NOT the same thing as a reduction in the number of neurons. Each neuron will have a lower response to the same amount of dopamine, but the neurons will still be there and will be healthy.
In Parkinson's, a specific group of neurons in the Substantia Nigra (which do happen to be dopaminergic neurons), selectively die off. They no longer release dopamine to their downstream targets, causing the motor and other affects characteristic of PD.
The compensatory mechanism you described is unlikely to cause those specific neurons to die, unless something far more complicated is going on, which you can almost never rule out but doesn't tell us much.
This gets really scary when you realize it's not just chemicals that we recognize as drugs that can have these effects- it's every chemical developed by every industry in every product we're exposed to in the world.
In a way it's nice and calming to think, "oh, if I don't abuse illegal drugs I'm not affected by this. Most non drug chemicals don't cross the blood brain barrier anyway"
Chemicals that the EPA tests for stop being produced, industrial chemist tinker with them in the exact same way these drug chemists do, and then new chemicals are released into our environment that we don't have data on or testing to mitigate.
> every chemical developed by every industry in every product we're exposed to in the world
Fyi, writing it like this makes you sound like the kind of person who thinks "chemicals" are "not natural" but produced by industry and therefore dangerous and evil. Even though literally everything is made up of chemicals.
Do you think it's safe to assume most Parkinson's suffers didn't abuse cocaine, or probably use it much if at all?
Do you think it's possible that long term moderate to heavy caffeine use could contribute to Parkinson's by the same method of action you have described?
I'm not an expert on any of this, medicine is just a hobby of mine. I don't think actual Parkinson's is caused by drug abuse though, I think it's a separate disease (or maybe more than one) that ends up doing the same type of damage to the brain so the symptoms look similar. Wikipedia seems to agree, we're not sure how most people affected got it. That seems to be kind of a theme in medicine.
As far as caffeine goes, I don't think it affects dopamine that much, so it probably wouldn't have that effect on its own. I can't imagine long term heavy caffeine use would be good for you though, I just don't think it would be enough to do the same damage that drugs that directly release dopamine do. Or at least, it would do different kinds of damage - my guess is memory issues due to lack of quality sleep and high blood pressure.
The fact that such a small dose of a toxic chemical could cause parkinsons in such an indirect way, to me, means that the cause of perkinsons is probably some environmental toxin that is interacting in some complex and novel way.
Well - there are a subset of PD cases that are identifiably genetically caused. It's likely more complex than just micro toxins, but it is possible that toxins in small quantities could play a role when combined with other genetic factors, etc.
There are chemicals that can kill you with a couple milligrams or less. I would bet that Parkinson's and lots of other diseases involving the brain will eventually be found to be symptoms caused by lots of different things, some genetic and some environmental, and probably lots of different combinations and proportions of each.
> There are chemicals that can kill you with a couple milligrams or less.
Obviously, but they are pretty straightforward things.
This chemical that causes Parkinsons is quite different, it has a complicated method of actually becoming active, and seems to target a very specific part of the brain. Unlike those other chemicals, this one is not something you could predict by simply looking at it.
Which is my point - the straightforward, or easily predicted chemicals we already are cautious about. The issue is the complicated or unexpected ones, the ones with very delayed effects.
I think I see what you mean. There's just so much we don't know at this point, and so many chemicals that we are exposed to even in small amounts, I could totally see some of these diseases being brought on by something common we've never considered. Or by some combination of things that may not be that harmful on their own.
One detail of the story that I still remember: the dealers of the MPTP heroin realized they had a bad batch and cut the price to get rid of it.