Determination of serotonin in microdialysis samples from rat brain by microbore column liquid chromatography with post-column derivatization and fluorescence detection.
The present paper describes a new method for on-line determination of 5-HT in brain microdialysates from awake rats by microbore column liquid chromatography with post-column derivatization and fluorescence detection. The derivatization reagent contained 1 mM benzylamine and 0.5 mM potassium hexacyanoferrate (III), both dissolved in a mixture of acetonitrile and 25 mM borate buffer (pH 11.0) (1:1, v/v). The limit of detection (S/N=3) for 5-HT was 0.5 fmol/20 microl. The samples were injected every 20 min onto a microbore column packed with C18 silica gel. The method exhibits an excellent stability over the periods of at least 12-24 h. The basal levels of 5-HT from 25 awake rats were 7.10+/-1.06 fmol/20 microl in the dorsal hippocampus and 4.64+/-0.91 fmol/20 microl (mean+/-SD) in the striatum. The 5-HT release increased to about 1500% during the perfusion with 100 mM K(+) containing Ringer solution or it was reduced to 60 or 40% during the perfusion with 1 microM tetrodotoxin or calcium free Ringer, respectively. The new method can be used to monitor extracellular 5-HT following acute systemic drug administration.
Yoshitake
T
T
Chemicals Evaluation and Research Institute, 3-822 Ishii Machi, Hita City, 877-0061, Oita, Japan.
Iizuka
R
R
Kehr
J
J
Nohta
H
H
Ishida
J
J
Yamaguchi
M
M
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D001923:Brain Chemistry / Q000187:drug effects / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005453:Fluorescence; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D017551:Microdialysis / Q000295:instrumentation / Q000379:methods*; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000032:analysis* / Q000378:metabolism; D012985:Software Design; D013779:Tetrodotoxin / Q000494:pharmacology
D012701:Serotonin; D013779:Tetrodotoxin; D011188:Potassium