Some do secrete dopamine. Dopamine is a metabolic precursor to epi and norepi. There are small amounts that get secreted, and certain rare subtypes of pheo will secrete dopamine. However, like everyone else said, dopamine isn’t able to cross the BBB so it’s not useful for treating PD.

It's very rare but possible. The majority of peripheral dopamine comes from peripheral sympathetic nerves which in part use dopamine to communicate. Some of this dopamine is taken up in the blood stream. Interestingly, there's almost as much dopamine in your blood as adrenaline though what it's doing there is not really known.

https://academic.oup.com/endo/article/151/12/5570/2456083?login=true

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3373991/

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Well, it IS a problem if you have both conditions. The pheo, and the parkinson's, as the dopamine precursors can also cause the tumors to oversecrete their usual levels.

And also some wild mood swings. There are some pituitary paragranulumas that do some pretty evil things. Even if somehow modified, to be a dopamine pump, pheos/paras do not really have an advanced structure inside like and actual organ, and as such you would not be able to get reliable levels out of such a thing. Unless you somehow fused one with a computer/implant, and had the implant juice the thing as needed. An idea that's at least 30-40 years away.

Now, what is a pheo "tumor", about 1 in 12 at autopsy have some kind of nodule that might be called a tumor, non-cancerous, and usually not active. How many people with parkinson's are irritating this natural feature? The technology is kind of a pain here. With an advanced enough one you can sometimes, maybe, pick up the larger ones using the Philips Affinity, Epic, or similar class using a stander C5-1 and tweak the settings a bit. And much of what's picked up is just scar tissue, and random junk, as the living core is usually as translucent as the organs around it.

Other than this, you have to pickle someone with tracers, and the usual song and dance with various types of medical imaging. And it probably doesn't matter, as you still don't know it its just the adrenal cortex being hyperactive, or the poorly differentiated lump, your Pheo producing the excess catecholamines.

So, the neurologist will usually just tweak the mix of drugs, and hope for the best. Because bringing in yet another specialist to decide, even with all the lab tests, and imaging, that yes, that is a pheo.. Is going to be a 2-5 year ordeal, with the patient, insurance company, and everyone else involved getting more and more pissed off.

Because what is a patient with parkinson's going to do, while off meds, for months and months, while in the lead up the surgery, taking alpha and beta blockers, and hoping the surgeon doesn't have a "whoopsie". Only for the remaining adrenal gland to have the same problem 2 years down the road.

Now there is fairly good results with veterinary medicine for treating those in dogs. But for humans, its still a dice roll that the surgery will kill you from the process itself, or stabilization issues with the organ no longer there secreting. And the chemo only route is generally only attempted in proven cancerous tumors.