Title:Detection of Melatonin Production from the Intestinal Epithelium Using Electrochemical Methods
Volume: 20
Issue: 30
Author(s): Paul P. Bertrand, Kate E. Polglaze, Rebecca L. Bertrand, Shaun L. Sandow and Maria J. Pozo
Affiliation:
Keywords:
Melatonin supplementation, serotonin, intestinal reflexes.
Abstract: The role of melatonin in the gastrointestinal (GI) tract had previously been limited to its well-described anti-oxidant properties.
Recent studies have, however, expanded the role of melatonin in the intestine, showing that it acts as a hormone with local paracrine actions
to modulate GI function and the release of other hormones.
The GI epithelium produces melatonin from the active precursor serotonin, which is thought to come from the serotonin synthesising enterochromaffin
cells (EC). The receptors for melatonin, the membrane bound melatonin receptors 1 and 2, are present on some smooth
muscles, neurons, and epithelium. Endogenous release of melatonin has been linked with secretory reflexes and the ileal brake reflex,
while exogenous application of melatonin in pharmacological doses has been associated with reduced inflammation in a variety of animal
models.
Recent studies have begun to look at melatonin release from the GI epithelium using real-time electrochemical detection methods. Using
these techniques, the time course of melatonin production shows similarities to that of 5-HT release while the ratio of 5-HT to melatonin
is altered during aging. In addition, the effects of melatonin supplementation on the production of endogenous melatonin and its precursor
serotonin are suppressed.
In summary, the role of melatonin in the GI tract is coming of age. There are many studies showing a clear role for endogenously produced
melatonin and clear effects of melatonin supplementation. Newly developed electrochemical techniques for exploring melatonin
availability in real-time promise to accelerate our understanding of GI melatonin in the years to come.
