Posted by JohnX2 on March 9, 2002, at 1:14:44
In reply to Re: Hypopthyroidism in people wioth mood disorders. » Psydoc, posted by Thrud on March 7, 2002, at 23:52:35
Thrud,I've looked into and also tried l-tyrosine and
also l-phenylalanine suplemenatation with short lived poop out
results. My understanding of the biological pathway is that the
amino acid in the vast majority of neurons already saturates
the bottlneck enzyme called "tyrosine hydroxylase".
phenylalanine (via phenylalanine hydroxylase)-> tyrosine (via tyrosine hyrdroxylase)-> l-dopa -> dopamine -> norepineprine
The phenylalanine is converted to tyrosine through
a phenylalnine hydroxylase enzyme. Subsequently tyrosine
gets converted to l-dopa via a "tyrosine hydroxylase" enzyme.
And then l-dopa can get converted to dopamine and then
potentially norepinephrine.In the vast majority of cells the diet swamps the enzyme
tyrosine hydroxylyse. So for most people taking tyrosine
precursor provides no benefit. However, you can bypass by
taking l-dopa as in parkinson's.Now for impotence, its interesting that we usually see this
a lot in medicines that are norepinephrine reuptake inhibitors.
A lot of people complained of this in Reboxetine. People found
relief for this with medicines that blocked the noradrenaline
"alpha-1" receptor like "Flomax". Also medicines with side effects
like priapism (permanent erection) such as Trazodone, block the
noradrenaline "alpha-1" receptor. So I wonder if your effect had
more to do with norepinephrine than dopamine.-John
> Hi Psydoc,
>
> Maybe you can help me with a little puzzle that has vexed me for a couple of years.
>
> A couple of years ago I tried l-tyrosine as a monotherapy for depression/panic/crushing fatigue because I was so sick of SSRIs. After about 2 weeks it really kicked in and I excitedly told my family that I felt well for the first time in 10 years. There was one major problem though...it made me completely impotent, more than any SSRI. In the end it pooped out after a couple of months and I had to move on to other meds.
>
> I did a lot of research on l-tyrosine to see where it is used in the body and see if I could pinpoint some biological basis for my problems: I simply shouldn't have felt that good (or that impotent) on a simple amino acid. I was using the standard dose of 1500mg per day.
>
> It seems to be involved in the endocrine system a lot, including the thyroid. I also believe that the thyroid is connected to sexual function (through some hormone I guess) but I could find nothing linking higher levels of l-tyrosine to impotence. In fact the opposite always seems to be reported: the increase in brain dopamine is supposed to increase sex drive. My TSH levels are tested periodically and have always been normal.
>
> I have celiac disease and know that there is some comorbitity with thyroid autoimmune problems. Could there be a thyroid problem which is not reflected in TSH levels? If it helps, I have just been found to be low in testosterone and LH.
>
> I have discussed this all this with my pdoc and he is referring me to an endocrinologist. In the meantime, if you have any insights to offer I would be very, very appreciative.
>
> Thrud
poster:JohnX2
thread:96147
URL: http://www.dr-bob.org/babble/20020307/msgs/97150.html