On Sun 07 Feb, Marty Polonsky wrote:
> In a message dated 2/6/99 4:32:16 PM Pacific Standard Time,
> [log in to unmask] writes:
>
> << Will A. Kuipers wrote:
> >
> > Marty Polonski and Will Johnnston seem to agree with Joe Bruman's theory
> and
> > advice to William A. Parrette that exercise will "use up" available
> dopamine
> > and that it would not be harmful to take a little additional dopamine to
> > offset the loss.
> > I beg to differ.
> > In my experience, not only exercise will cause an increase of tremor, but
> > any kind of stress, or excitement, like getting up in a crowd and speaking,
> > will do that.
Hello Marty, I hope you don't mind my jumping into the middle of an on-
going debate, butI missed the start (probably searching another part of
the haystack looking for interesting letters.)
I have had discussions on this subject before, but I don't think we
reached a firm conclusion. I think the following points may tend to
support your view, and maybe explain why.
1/ Dopamine's function is essentially to 'bridge the gap' which exists
between the Axon and the Dendrite by, filling the space between them (The
Synapse with a conductive medium so that the elrctrical signal which
follows a split second later will have a smooth uninterrupted journey
from the brain to the muscle.
2/ The quantity of dopamine required to bridge the gap is not related
to the level of effort being expended. (At least not to a first order of
magnitude).
3/ my own experience of running (Sounds better than jogging) supports
this view, and I find no need to increase the level of dopamine.
4/ There is a mild apology to be made to the above statements:- The rate
of flow of blood in the body will increase substantially, with the result
that that part of the time which the levodopa spends in the bloodstream
will be reduced - perhaps even by half. However, that is half of a fairly
small number in the story; my guess would be that since the total time for
the transport from the mouth to the lower intestine; from the lower
intestine to the blood stream; from the blood stream into the brain,
and finally through the brain to the Substantia Nigra, is about 1 hour
for Sinemet 100/25 , the reduction in overall time would be about 5
minutes. This shortening of the timescale will raise -slightly - the
dopamine rate of flow, which means a small increase in dosage ( about 4%)
and your tablet may run out about 5 minutes early.
5/ Now let's introduce another factor which complicates the issue -
Stress and the production of Adrenalin. I chose a subject like jogging
deliberately, because there is hardly any competitive pressure, but if
you were playing a hard game of Squash, tennis or any exercise in which
the will to win is an important factor, then you will produce adrenalin,
which will accentuate your tremor, and I believe that it is this adrenalin
and its amplifying effect on our Parkinson's symptoms that causes us to
incorrectly blame the exercise.
(Sorry I took so much room - once I get going it all seems to flow
automatically)
Regards,
--
Brian Collins <[log in to unmask]>
