Charles & others,
There are various references on the medical web sites to Cholecystokinin in
Parkinsons.
They take some finding, but here are two quotes to show we are not barking
up the wrong tree:
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Details of a grant for research, listed on the Harvard site,
<http://neuro-chief-e.mgh.harvard.edu/parkinsonsweb/Main/Support/usgrants.html>
details as below:
11.Transmitter and Tropic Regulation of Nigrostrial opamine Neurons at the
Pre and Postsynaptic Level by Neruotensin and Cholecystokinin
Peptides. Possible Opening for New Treatments of Parkinson's Disease
Sergio Tanganelli, Ph.D., Principle Investigator
Ist. Pharmacolgy
Ferrara, Italy
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<Web page http://www.biogenes.ipw-berlin.de/igy.htm>
part quote:
R. Schade, P. Henklein, A. Hlinak , Humboldt-University Berlin
Cholecystokinin octapeptide (CCK-8) is a neuropeptide which is colocalised
with dopamine (DA) in mesencephalic brain regions [substantia nigra (SN),
ventral tegmental area (VTA)] .
Since dopamine is particular involved in degenerative diseases of the CNS as
e.g. Parkinson's disease the coexistence of DA with CCK-8 is very
interesting. Many investigations were
started to study the biological significance of interactions between these
both neuronal substances. One animal used for such studies is the unilateral
disturbance of the dopaminergic
nigrostriatal system by injection of the neurotoxin 6-hydroxydopamine
(6-OHDA) into the median forebrain bundle which results in a complete lost
of catecholaminergic neurons located
in VTA and SN. This lost is also seen in dopaminergic fields of termination
as e.g. striatum (STR) and nucleus accumbens (NACC). However, with respect
to CCK-8 there are confusing
results obtained by radioimmunological, immunocytochemical and in situ
hybridisation studies, respectively. These differences certainly are due to
the methods used and, in particular,
due to the specificity of the utilized antibodies (Ab). The main
inconsistency between these methods concerns the following results: CCK and
DA are colocalised in a major population of
nigral neurons (approximately 70%). There is a dramatical fall in DA in both
SN and STR. Despite of the high portion of cells with DA and CCK-8 in
colocalisation, the nigral CCK content
is substantially reduced in contrast to a nearly unaffected striatal CCK-8.
At present this contradiction is not convincingly explained.
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Ernie.
Ernie Peters <[log in to unmask]>
