Chromium treatment decreases the sensitivity of 5-HT2A receptors.
BACKGROUND
Recent case series suggest that chromium picolinate in doses of 400 microg daily may have antidepressant properties, perhaps through increasing the peripheral availability of tryptophan for brain serotonin (5-HT) synthesis.


OBJECTIVE
To determine the effects of chromium treatment on plasma tryptophan availability and on brain 5-HT function in human and animal models.


METHODS
We studied the effects of short-term chromium supplementation on plasma concentrations of tryptophan and other large neutral amino acids. Brain 5-HT function was assessed by measuring the corticosterone/cortisol response to the 5-HT precursor, 5-hydroxytryptophan (5-HTP), a response believed to be mediated via indirect activation of 5-HT(2A) receptors.


RESULTS
In rats, chromium increased peripheral and central tryptophan availability and elevated brain 5-HT content. Changes in peripheral tryptophan availability were not seen in humans but in both rats and humans, chromium lowered the cortisol response to challenge with 5-HTP.


CONCLUSIONS
Chromium can modify brain 5-HT function in humans and animals, perhaps by altering the sensitivity of central 5-HT(2A) receptors.
Attenburrow
M-J
MJ
University Department of Psychiatry, Neurosciences Building, Warneford Hospital, Oxford OX3 7JX, UK.
Odontiadis
J
J
Murray
B J
BJ
Cowen
P J
PJ
Franklin
M
M
D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002857:Chromium / Q000494:pharmacology*; D003345:Corticosterone / Q000097:blood; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D016037:Single-Blind Method; D014364:Tryptophan / Q000097:blood
D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D002857:Chromium; D012701:Serotonin; D014364:Tryptophan; D003345:Corticosterone