I have also read repeatedly that human mast cells do not contain 5-HT. But,
to my knowledge, it exists no systematic study proving this. If somebody
knows a such study, please let me know where I can find it. Furthermore, we
are discovering more and more phenotypes of mast cells which can be
characterized morphologically, biochemically and functionally. Did any
study concerning the amine content of these various phenotypes has been
performed ? I just can say that we have looked at the presence of 5HT and
tryptophan hydroxylase in human mast cells from the dura mater and head
arteries without success. But this does not signify that other mast cells,
which can be present under some pathophysiological circumstances, do not
produce the enzyme and the amine. For example, we have measured a peak of
5-HT under the temple skin of cluster headache patients during the attacks
(see Aubineau et al., The Lancet 1992, 339: 1294-1295) but we could not
explain clearly what could be the source of this 5-HT. Mast cells,
platelets or degenerating sympathetic nerves ? (several studies show that
principal sympathetic neurons can synthesize 5-HT under certain
circumstances such as tissue culture in presence of particular substrates.
If produced, this neural 5-HT could also play a role in inflammatary
phenomena).
Pierre Aubineau
Physiopathologie vasculaire.
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F. Frank LeFever <flefever at ix.netcom.com> a écrit dans l'article
<5hci8l$hi1 at sjx-ixn5.ix.netcom.com>...
>> In the response to this query (v. infra), reference was made to 5HT
> secretion by mast cells. I have read repeatedly that this is a
> characteristic of RAT mast cells, but not of human mast cells