Simultaneous measurements of tryptophan and its metabolites, kynurenine and serotonin, in the superficial layers of the spinal dorsal horn. A study in normal and arthritic rats.
It has been demonstrated that 5-hydroxytryptamine (5-HT) is not the only neuroactive metabolite of tryptophan (TRP) in the CNS. The presence of kynurenine (KYN) and its metabolites has been reported in the brain of several mammalian species and the neuroactive properties of these compounds are now well established. In the present study, we report the identification of KYN in the superficial layers of the rat spinal dorsal horn. KYN was measured simultaneously with TRP. 5-hydroxytryptophan, 5-HT, 5-hydroxyindoleacetic acid and 5-HT-O-sulfate by means of liquid chromatography with coulometric electrode array detection. The results observed in the normal rat and in an animal model of persistent pain, the arthritic rat, are discussed in view of the hypothesis relating to the involvement of the bulbospinal serotonergic system in pain mechanisms and of the possible participation of KYN and its metabolites in these mechanisms.
Godefroy
F
F
Unité de Recherches de Physiopharmacologie du Système Nerveux de l'I.N.S.E.R.M. (U. 161), Paris, France.
Matson
W R
WR
Gamache
P H
PH
Weil-Fugazza
J
J
D000818:Animals; D001168:Arthritis / Q000378:metabolism*; D007737:Kynurenine / Q000032:analysis*; D008161:Lumbosacral Region; D051381:Rats; D012016:Reference Values; D012701:Serotonin / Q000032:analysis*; D013116:Spinal Cord / Q000378:metabolism*; D014364:Tryptophan / Q000032:analysis / Q000378:metabolism*
D012701:Serotonin; D007737:Kynurenine; D014364:Tryptophan