Simultaneous fluorometric measurement of histamine and tele-methylhistamine levels in rodent brain by high-performance liquid chromatography.
An improved high-performance liquid chromatography (HPLC) method was developed for simultaneous analysis of histamine (HA) and tele-methylhistamine (tele-MHA) levels in mouse and rat brain. The method consists of a solid-phase extraction (SPE) and subsequent HPLC with postcolumn derivatization of the amines with o-phthalaldehyde. The recovery rates of HA and tele-MHA during the SPE procedure were 82.8+/-3.4 and 86.0+/-1.7%, respectively. The detection limits for HA and tele-MHA were 8 and 12pg, respectively, with sufficient linearity up to 30pg. Using this newly developed system, we observed that the brain tele-MHA levels in H3 receptor knockout mice were significantly higher than those of wild-type mice by 2.1-fold. Furthermore, we also observed that the brain HA and tele-MHA levels in Zucker rats were significantly lower than those of lean rats by 76.6+/-5.3 and 77.8+/-5.0%, respectively. These observations coincided well with those of previous studies using radioimmunoassay or HPLC with precolumn OPA derivatization, confirming the utilization of the assay system.
BANYU Tsukuba Research Institute, BANYU Pharmaceutical Co., Ltd., Tsukuba, Ibaraki 300-2611, Japan.
Yasuhisa
Y
Miyamoto
Ryo
R
Yoshimoto
Mariko
M
Yumoto
Akane
A
Ishihara
Kazuhiko
K
Takahashi
Hidehito
H
Kotani
Akio
A
Kanatani
Shigeru
S
Tokita
D000447:Aldehydes / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D000818:Animals; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D005470:Fluorometry; D006632:Histamine / Q000032:analysis*; D008297:Male; D008722:Methods; D008761:Methylhistamines / Q000032:analysis*; D051379:Mice; D008813:Mice, Inbred ICR; D018345:Mice, Knockout; D009765:Obesity / Q000378:metabolism; D051381:Rats; D011924:Rats, Zucker; D018100:Receptors, Histamine H3 / Q000235:genetics / Q000502:physiology*
D000447:Aldehydes; D000588:Amines; D008761:Methylhistamines; D018100:Receptors, Histamine H3; D006632:Histamine; C020404:tele-methylhistamine