Serotonin (5-hydroxytryptamine, 5HT) is one of the most potent monoamine neurotransmitters and peripheral signaling molecules able to act as a paracrine, endocrine, and exocrine messenger. While blood platelets only rely upon 5HT uptake for their stores, serotonergic neurons [of the nervous system and intestinal myenteric plexus] and gastrointestinal enterochromaffin cells can both uptake and synthesize 5HT from its amino acid precursor – L-tryptophan. Serotonin is also synthesized in the pineal gland as a precursor of melatonin.
Physiologically, 5HT has complex and diverse effects on the central and peripheral nervous systems, as well as on neuroendocrine regulation and immunological responses. However, it is also involved in the biochemistry of several pathophysiological conditions including many neurological disorders, gastrointestinal dysregulations, and cancer.
Our antibodies and ELISA kits
Therefore, tools allowing for the evaluation of serotonergic systems might be valuable to approach the complex 5HT activities in physiological and pathological situations, but also to investigate mechanisms of action of novel disease-targeting therapies.
For this purpose, we have set up and validated a series of experimental immunoassays specifically raised against 5HT; either ELISA kits for the determination of 5HT content (#BA-E-8900, #BA-E-8900R), or antibodies to approach its localization and functional networks (#IS1086, #IS1035, #IS040, #IS1007). Our tools are compatible with varied types and natures of samples, originating from different species.
Cancer cell lines display a differential serotonin production activity.
(A) To characterize their ability to synthesize serotonin, a series of human tumor cell lines were seeded and left untreated or treated with the tryptophan hydroxylase 1 inhibitor – telotristat. Culture supernatants were then collected and processed for serotonin and tryptophan (data not shown) level determination using ELISA kits (#BA-E-8900 and #BA-E-2700, respectively).
Among this series, QGP1 and H2196 cell lines are shown to produce higher levels of serotonin ; such a production being inhibited in the presence of telotristat.
(B) In QGP1 cells, telotristat dose-dependently inhibits serotonin production, with a maximal effect at the highest dose where serotonin amount is as low as in the control medium.
Immunohistochemistry against serotonin (5HT) on FFPE human tissues. 5HT immunoreactivity, revealed using anti-serotonin (5HT, rabbit polyclonal antibody #IS1086), is highlighted in enterochromaffin cells of the intestinal mucosa of a healthy colon coronal section (A), and in neuroendocrine tumors (B&C).